As far as an adult Halloween party...

I lived in Austin for a while, I can tell you that the area downtown known as "6th street" was one of the biggest Halloween parties I have ever seen.

6th Street is where many of the well known bars and clubs are, and is normally a large party on the weekends, but on Halloween all the cross streets are closed off and thousands of people are there. This is NOT for kids, and there's no telling what you will see. Well, you'll certainly see a lot of inebriated people, but there's no telling what else...

All of the bars will be open until 2AM. There's no way anything is closing early.

Here's an image of the 2015 celebration. It's huge.

If you are staying in a residential neighborhood, you can pass out candy to kids coming to your door. Just go to the grocery store ahead of time and buy a few bags of pre-wrapped small candies (the stores will have large displays of these, it will be impossible to miss). About the time it gets dark until around 8:30 or 9:00, kids will come to the door and say "Trick or Treat", then you give them each a piece of candy. Having your front porch light turned on is your signal that you're handing out candy. It would be useful to ask your air bnb host if their neighborhood has a lot of trick-or-treaters. It can really vary by neighborhood and street. Areas with lots of kids will have more activity than others. Of course in Texas you can just ask strangers for info, Texans are really nice!

I live in Austin. If you're really looking to party hard, 6th Street is the way to go. If you're looking to experience an authentic, boring, adult-style American Halloween, passing out candy from your AirBnB is a great idea - this is what Halloween is really like for most adults in America! If you're looking to have a little more fun (but not 6th Street fun), you might want to check out what's going on at, for example, the following locations:

• Alamo Drafthouse
• Highball
• Punch Bowl Social

If you're really looking to experience a "true" American Halloween, I would definitely stay in the city.

Another suggestion is to find a nice part of town (Westlake, Northwest Hills, etc) and just walk around. You can soak in the Halloween vibes and scope out the yard decorations and costumes, which are likely to be nicer and more splashy in a nice part of town. Trick or treating is really the essential Halloween activity, and it more or less amounts to wandering around residential neighborhoods. I would not suggest asking for candy as an adult, you will get funny looks.

There are many great answers, and you have some options open to you if you AirBnB it. I would ask any potential host if there are children in the area citing your interest in passing out candy.

Here is the key: The better the candy you pass out, the more kids you will have. I have bought cases of full sized candy bars and handed them out. You can typically buy these at warehouse clubs for about 25 cents per bar. They will also have large bags of the smaller sized candies and you can give each kid several (rather than one) of the small bars making your "home" a desireable place to trick or treat.

My wife and I typically sit out on the front porch handing out candy. This way kids don't have to guess if we have candy. (We live in Florida so it is not cold in October.)

My wife and I typically dress up and hand out candy. Nothing to scary for the little kids. Also our dog has several costumes and joins the fun.

We typically offer parents their own treat. "Want a beer dad?", I will have some on ice.

We never turn away teenagers/older kids. Some people get upset at this, but we don't. They could be throwing eggs at houses or stealing candy from younger kids. It's even okay if they are not wearing a costume. Heck, it could even be a large child, who are we to judge?

Then around 9:30 or so, the kids will stop. It's time to hit the clubs!

Good luck.

At Halloween, Adults go to dress up parties, either private parties (friends...) or go to bars or clubs; the later usually have prizes for best costumes.

Halloween is not an "official" holiday, so shops and bars will have their regular opening hours.

There might be public organized events for families (check the local Austin event guides)

If you want to see kids trick or treat, then you should find yourself a nice suburban neighborhood and walk around; in that case, I would not go dressed up as to not confuse people of your intent (IMO)

You do the treats.

If you do go to AirBnB in a neighborhood, just buy some cheap candy and dress up in a costume and hand it out. As a plus, I like to have some cheap (boxed) wine poured into plastic cups along with a bit of cheese in toothpicks for the adults that are taking their kids around.

In my neighborhood I counted 300+ kids came by (but it's a well-established, affluent neighborhood*). And most of the adults LOVED the wine idea. Just turn your lights off when you run out of candy, and the kiddos know you're out. Extra fun is to make a jackolantern. Turn that candle out when you're out of candy as well.

*- I am not rich; I rent my house!

It's important to remember that Halloween is, at it's heart a harvest festival. For a lot of people it's that "start of the fall season" even though not technically correct. You will see a lot of different things, a lot of them having roots in harvest festivals you may be used to.

Things to be aware of:

Halloween is in part a children's holiday. From dusk-ish til full dark (and some times after) children will run around begging candy from strangers to the sound of "Trick-or-Treat". If your home during these hours expect to have to dish out some candy. Buy some individually wrapped candies. The stores will have rows of the stuff this time of year. 2-3 bags should be enough.

You can opt out of the great candy give away by turning off your porch light. When the porch light is on, then your givin' it away. Porch light off, your a weirdo - shut in who doesn't like kids.

During the daylight hours it's not unheard of to have children and adults ware costumes to work and school. So be prepared for that. For adults companies usually state that you can ware a costume or not. Just remember that work costumes still have to be decent.

After Dark - This is when the fun begins for adults. Some people have costume parties. You can go to one of those. Make sure to check the "costume type". Many private parties (and clubs) have a theme. Make sure your comfortable with the theme. Some times, they may be more interesting then others. Boundaries of decency are usually pushed at these parties. Doesn't mean you have to, but someone there usually will. Make sure your comfortable with that.

Theme Parks and the like will usually offer "Haunted Houses" or "Halloween Nights". Those can be fun. If you ware a costume keep in mind you still have to get through security.

In short, Halloween can be broken down into 4 main parts. You can take part in as many or as few as you like.

1. Family Harvest fun. This includes Pumpkin carving, hay rides, farm visits, and fairs. These are usually done during the day. Theses are family friendly.

2. Candy Begging. Usually from just before dusk (young children and parents) to just after dark (young teens, no parents). Remember, light on = your giving away candy, light off = no candy

3. Scare the crap outta ya. It's fun to be scared so there are movies and scary things to do from haunted houses to horrible B movies at the theater. Some are scary, some are just god awful tacky. Make sure if you do movies you try and watch both. These go all day and night, usually later at night = more scary but that's not always true.

4. Masquerade! These are usually at night, and generally not kid friendly. The general idea is "any thing goes cause I got a mask on". Make sure that when you choose your venue for "any thing goes" your comfortable with the definition of anything that the location is using. Sometimes it's just drinking and sexy costumes, other times it's dancing with people in their favorite cartoon costumes, but there are places that are much more liberal with their definition of "anything". What ever you do go with friends you trust. That's just a good all around party rule.

I love your question. Halloween is a great holiday. Like others have said, many people frown upon adults or even older kids, like teenagers, trick-or-treating. But yes you could make friends with someone with children and tag along. The adult party experience is more like a rave type party than traditional Halloween you see in movies. But it is still fun. The dressing up in costumes is key, for both kids and adults. Also the handing out candy can be fun. Just talk to people and I'm sure you will find a good time. Whenever I travel, the best times happen when I talk to strangers.