The main thing you need to focus on is BR management. If you follow that and move up when your bankroll (and winrate) dictates that you can, and move down when your bankroll tells you the same you should be fine. Remember not to chase your losses and not to play above your roll most importantly.

I'm not sure you understand that poker is a grind and that it will take a while to make a sizable amount of money at it. So if you want to do this right, look in BR management and determine where your BR allows you to play. After that you should head to forum that corresponds to the game of your choice here on FTR, and begin reading every article you can find in the digest. Post hands, entire SNG tourneys, and any other questions, and that will help determine whether your game is on point or you luckboxed your way to $15k.

Anyways, just remember that your BR is no longer 15k and that if you think as such you will go busto again.