Dubai International Airport services

Dubai International (DXB) airport has 3 terminals. Terminal 2 is used by Flydubai and a few other budget airlines whereas Terminals 1,3 are used by Emirates and other major airlines. Coming to your questions.

1. Yes the airport and all facilities in it are open 24 hours a day 7 days a week.
2. Yes there are complimentary showers located in the facility.Showers

Dubai International: Use our complementary shower facilities located on the departures level of Terminal 3 (between gates C18 and C22) and (between gates B13 and B19 and between gates A1 and A24).

3. There are a multitude of lounges available. For all passengers i.e. economy, business etc. If you are an economy passenger you can use any of the economy lounges for free and pay the fee to use the premium lounges. I would suggest to look at all the facilites on the airport's website and plan your transit time ahead. Website : http://www.dubaiairports.ae/while-youre-here/

Apart from your questions, the airport will have restaurants, sleeping lounges, charging booths, restrooms, smoking areas, shopping areas, currency exchanges, WiFi and a number of other facilities. I would strongly suggest to take some local currency (AED) with you instead of using the airport currency exchanges.