I bought this bike like an hour and a half ago for $60 and I cant find the exact model. I am not really a bike guy so I'd appreciate some help :)
bTwin is the bike brand from the big French multisports chain Decathlon. Their bicycle sales are quite big in France, Spain and Belgium. Rockrider is the name for the MTB line. Usually there are numbers attached to indicate its rank. From your picture it is probably their Rockrider 5.2. This is an entry level type. It dates from 2005-2010.
See a review of the Rockrider 5.2 in https://www.bikeradar.com/gear/category/bikes/mountain-bikes/product/review-decathlon-rockrider-5-2-8964/