What a fabulous start. Your top is beautiful! And taking on hand quilting warms my heart. It's what I always do.
I would go out an get a roll of 1/4" quilting tape. Decide what elements you want to quilt . You don't have to do all of them. I would probably just do the "backgrounds" ( 1 from the corners) and the pieces just outside the pinwheels. That should be close enough. Put the tape next to the seam line and quilt along the tape around the shapes.
Learning to hand quilt takes time and patience. Lots of straight lines should be good to practice on. Watch the miracle happen as your stitches get to a consistent length. Small stitches take time. Be patient. And proud of your progress as you go along.
Good luck in whatever you choose to do!
PS - I have never used spray basting. I always do it by hand - with thread.