I'm a french girl and I go to Cancun with a friend for 2 months. Problem: we don't know where to sleep because some areas are so expensive. If you know good and cheap youth hostel or a mean of making a "colocation" (sorry for my english)^^.
Your english is fine there.
You have to stay out of the "Horseshoe Of Hell" and stay in town, if you are on a budget. There actually is a real town of Cancun where regular Mexicans live and the prices are cheaper. Once you land in Cancun, take a shuttle to where the bus station is and there are a bunch of hostels there that are cheap (er). Once you get that settled, you are Golden. Cancun is set up so girls drink for free. That brings in the men.
PS I hate Cancun. Blecch and glurgh.