Ring games and MTTs are two different beasts.

Just to give you an example, I'm a huge winner at NL100 and NL200 (mostly at UB too). I consider myself to be a pretty good NL ring player.

However, when it comes to SNGs (20$-30$ buyin), I'm mostly a break-even player, maybe a little profit but nothing compared to rings.
And it gets even worse with MTTs (10-20$ buyin). I simply can't play them. I probably look like a fish when I'm playing a 10$ MTT but I can beat NL200... go figure!

So doing well in ring is not a guarantee to do well in MTTs. If you are just starting, I think it is a good thing to experiment all sort of games to see what you like and do best. Most players will do better in a particular game. I came to the conclusion that I needed to stick to NL ring for now and occasionally play small buyin MTTs just for fun.