what would be the best way to build a bankroll?

My personal choice is cash ring games, the best thing about them, is you can leave at anytime, so if it not a good table, you can find another 1, unlike MTT where you are committed to giving away your chips, + MTT are only just bring a profit, unless your in the top 3.

Grind at the 1/2 cent ring game

Well that's not that much to start with. With $30, you don't have alot of options but it's still up to you to know what games your good at. I, personally, would grind at 2nl with that kind of starting br.

WIN

posting about your 30 dollars aint helping your bankroll