It seems that you have a tension problem. When I started, I had the same problem. Had to take the machine back to the place (LQS) where I bought it. They fiddled with the bobbin tension as well as the needle tension. Havn't had a problem since and it's been several years. I think the machine just needed to be beat into submission, and now she is behaving. You know she needed to understand that I'm in charge!! By the way--your quilts look good for just the second attempt. You are indeed brave to jump right in!!!
Sue