If you have never attempted FMQ'ing before but still want to try it I would first suggest that you take any kind of scrap fabric and make a few sandwiched squares and practice on those until you get to where you are happy with the results. Then you can switch over to the quilt and go at it.
I would do in the ditch on the large center with the pin wheels and for first timer FMQ'er I would use a merandering stitch. The best way to describe it is it kind of looks like brain coral, curving lines that run back and forth.