Pokerstars had some sort of promotion, where the play money players all received 5 dollars in real money. After quitting for a long time, i finally started playing poker again

Anyways, I headed off to the lowest micro stake at 2NL. After a few hours of play, I got my bankroll to $11. I read the bankroll management guide and it recommended me have 15-30 buyins.

1. Does this mean I was suppose to have 30-60 dollars before even playing 2NL?
2. Also, when should i move up to 5 NL?
3. I had KK and there was a raise, re-raise in front of me. Can i just shove here?
4. If you have a high pocket pair (raised preflop and got called) and an overcard comes off, what would it take in order for you to release your hand?