Dianne,
Start in the very center of the quilt and do loops. First go clockwise, then the next one goes counter clockwise, making it easy to move around the quilt. It doesn't matter if they are all the same size - actually it looks better if they aren't!
It will also help if you use the gloves made for quilters - they help you maintain your grip on the quilt. And don't forget to lower your feed dogs and loosen the tension on your bobbin and top thread.
Relax - it's supposed to be fun!