Congratulations - I think my best advice would be to take all the lessons you can get free and/or afford and practice, practice, practice. I have a girlfriend who takes the lessons with me and she uses my machine too. I love having a buddy who is learning with me.
I haven't found the longarmers here too forthcoming with help, but maybe it's because I don't know what questions to ask - or they have been at it so long they have forgotten what it was like to be a newbie.
I have been working furiously to get some of my own tops constructed to practice on and a group that I quilt with from time to time is keeping me in charity quilts. Right now, I have four of theirs to do. I am practicing meandering on most of them.
I have never quilted my quilts before getting my Gammill so this step is totally foreign to me and I really am starting from scratch.
I also keep a log of the quilts I am doing and when I learn something new, I keep that in my notes - like making sure tops are printed so intersecting seams are flat - they are hard to quilt over and if you quilt around them, they form peaks ... I learned the hard way ... thankfully on my own little quilt. I also learned that stitching close to applique wasn't as hard as I thought it would be - just went slow. Go slow around the curves to avoid stitches that don't lie flat on the back (tension).
Don't be afraid to post questions - someone might have a suggestion
Relax and enjoy your machine.