And before you say do them all,
Stay where you are. Why do you have to change if you just want to move up the ladder of the 6max games?

I play MTTs, full ring, and 6max games though after playing just 6max for a couple months my MTT game suffered so it may not be such a smooth transition esp. if you aren't use to full ring. So I would play full ring NL and when you feel compfy with that move to MTTs.