whether or not you "need" to quilt in the star centers will depend on the batting you use. the manufacturer's instructions should tell you how far apart your quilting can get. you'll probably find you don't "need" to do the extra quilting.
don't pressure yourself to add anything you don't feel ready for yet. i turn green with envy and sigh wistfully when i see the beautiful hand and machine quilting many of our members do. unfortunately, my own skills in that regard are still very limited. (i've learned to "love" the minimalist approach to the quilting phase of a project. :wink: :lol: :mrgreen: )
that said, i have a feeling you might be more pleased with the results and with yourself if you added a little something to the stars. even something as simple as diagonal lines from block corner to block corner, so they run through the centers will add pizzazz without giving you a nervous breakdown.