How to rent a timeshare week?

My wife and I had just returned from Cancun we purchased a studio for $ 12,000 they stated we can rent our weeked, they gave us unlimited usage but it seemed confusing when they stated we can only use the Cancun resort every 2 years and would have to go else where if we use a vacation next year. I ask every employee how you rent out a weekend and no one seems to know hot to answer this.also what do they mean unlimited usage? if we can only use the cancun resort every 2 years.