Leah Day is AWESOME and recognized as an expert, so you can watch her videos with confidence that you are getting good advice.
A walking foot is definitely a big help. I don't know what machine you have, but when I got a walking foot for my brother, the lady at the store actually recommended the generic one she had.
You are also right on when you talk about an extension table. A quilt gets heavy and having it supported well is very important. (IMHO) You should see what my set up looks like when quilting a big quilt....a fold up portable table behind my machine, a table to my left side (or ironing board) and then the rest thrown over my shoulder...quite a sight! ;-)
Yep practice does make perfect, just hard to admit that when I want to be perfect, NOW!
Good luck and have fun!