Wow... for your first quilt, you did an amazing job lining up all that sashing!
An easy quilting pattern would be to make vertical wavy lines. Start in the middle and then work right and left from top to bottom of the quilt. You can use your walking foot and just curve it to make the wavy lines. I've done them about 3- 4" apart for some quick, easy quilting.
hint: With every line sewn, take a look at the back to be sure you don't have puckers or any other problems.