Congratulations! I have had my new to me LA about a month now. My initial practice piece was a quilt sandwich with a thin batting about 3 x 3 feet which I then cut up into potholders and have added a piece of insulbrite and new backing.
Have you been FMQing on your domestic? If so you have developed some muscle memory, ie simple meandering.
Do you have a quilt flimsy already to go? For my next "practice" I put a scrappy top and started with a meander and in no time had a full size quilt done. I figure I might as well have something to show for my practice work. The meander quilt helped me learn to gauge how far I could quilt before I reached the front edge. I put Quilt #11 on the frame last night a HST scrap baby quilt for donation and each one has been a learning experience.
Get yourself a notebook and list Date, Description, Size, type of batting, backing and thread. Make note of the stitches that you have used. Make notes on what worked and what didn't...things like tension, thread breakage. It takes little time and you will be glad you did. Oh and look at the many tutorials on line. I have a large white board (18" x 24") and practice doodling every once in a while. And most of all have a great time!