I wanna start grinding those at pokerstars and learn about mtts are they a waste of time? I am a broke student so my bankroll is about 20$

I personally feel that SNG's are a perfect place to start, if firstly, you want to just get a ton of experience, in terms of playing a lot of hands and getting a feel for how online poker plays while also, secondly, doing in for as cheap as possible, you should definitely jump in a few SNG's.

It would of been easier for us to advice you, if you told us a little about your poker background and experiences, but at any level you should consider studying the game to master your stake level.

A lot of the big name pros started with SNGs. They are a decent way to build a bankroll, with less variance than you get in big field MTTs.

posted by op in one of his (many, many) threads.

Op if you want to become a decent poker player (as a rec, or something more) there are some well-established truisms:

Find a format you enjoy and stick it to it (you hop about from format to format like a grasshopper on speed)

No more than 50% of your poker time should be spent playing. The rest should be spent learning, and in a structured planned manner.

Learn and conquer the mental game. Read and understand both of Tendlers books.

In forum, post your hands in the correct forum, in the correct manner and learn to listen to all advice, constructive or otherwise.

These are just basic baby steps...if you can't do them, poker is not for you.