Quoted By:
if you can afford a $550 bike, get the Talon 29 3. It's got all the basic features to learn how to ride, and the rims are tubeless ready. Then if you get really into mtb you can upgrade.
If that's too expensive, you gotta go used. Expect to pick up a bike for $100 and put about $200 into it to get it running correctly. If you got a bike coop or bike kitchen nearby you can do some work yourself and save some money.