Required documentation for travelling to the United States from Canada? [closed]

I got an opportunity to work in Las Vegas in a hostel - I clean for four to six hours a day and in return, I'm getting a free bed. I still have to pay for food and what not. I'll be staying for three months and then returning to Canada to work in another hostel in British Columbia.

I thought that since I was Canadian, and I technically am getting no pay and still have to mostly support myself beside a free bed, it would count as me visiting/a vacation, which (I think) means I don't need a visa of any sort, just a passport. I'm starting to worry that maybe I am misunderstanding things though and I thought I'd ask here for some clarification.

Any help is appreciated!