Here are some things to try with free motion. The first two are the easiest to do. Cover a whole quilt sandwich with these two until you get a feel for it. HINT -make sure that you leave an inch all the way around the quilt sandwich as you need to have something to hang onto.
The spirals are interesting. If you go into the center without stopping you will get the smooth circle on the left. Try going into the center and then back out. To get square corners stop where you want the corners to be, take a few stitches in one place and then move to the next corner.
Loops are lots of fun. Try e's, l's and upside down loops. Don't worry if you are wobbely, the more you practise the smoother your free motion will become.