Snowboarding 101.
1) Don't ride flat(unless you have a new reverse camber board). You want to be riding on an edge the whole time. It takes a while to get used to but it's second nature after a little bit. Riding flat on a regular camber board is a really easy way to catch an edge and bail. You also have less control and wobble all over the place
2) I find my back foot controls my carves by just kicking it out. So I'd suggest a nice easy/somewhat straight slope to work on your carves/transitions.
3) Don't take too long switching from a toe side carve to a heelside carve. When your new your going to fall or spin out. The longer you take to switch sides the longer you ride flat for, unless you hop from side to side
4) Get practice and have fun! I never took lessons, and I'd say I'm pretty good. It's all about practice.