I think I ride with the board sort of flat.. How would I ride kind of straight while keeping my edges lifted??
Only time you'll ever need to ride straight though is a cat track, runout... If you find yourself bored on the runs you're on and turning slows you down too much, head to a steeper run. I find most people when learning to board do better on runs with some decent slope to them (i.e. a mid-range blue square) to help them get more used to full on edge control and carving.
Start learning to do S and C carves on a blue and you'll find the edge control you were missing. It's all about carving. No offence to any of the noobs out there, but my guess is 95% of them that come on here and say they can "carve" aren't even close, they're doing intermediate/dynamic slider turns.
Have fun and don't worry about falling! I still fall every day on the slopes...