if youre gonna be playing poker with the $50, join a table where you can buy-in at least 5 times juss to be safe (youre juss learning anyways). youre best bet to learn is to play low/micro-stakes tables because there'll probably be people juss like you at those tables so you dont needa worry bout pros.
1) play a tight/aggressive game, tight meaning you only play premium hands, or blackjack hands that add up to a number close to 21 - preferrably 18+ (face cards = 10, all the other cards equal their number), or pocket pairs such as 77,88,99,etc. fold all other hands cuz theyre 80% of the time worthless. aggressive means constantly raising but only if you have a good hand. playing this way can get boring but its best way to play poker (most, if not all the pros play a tight/aggressive game)
2) dont be afraid to fold if you think youre being beat. youre not gonna win by throwing more money into the pot