Welcome aboard!
Do wash the flannel first, if you are using strong colors I'd also put in a dye magnet/color catcher so you can see how much (if any) dye is cast off. Personally, I don't like working with flannel but I didn't realize that for a long time. Finishing up a donation quilt now that is reminding me of this...
I personally prefer a higher loft poly batting than warm and natural. The W&N is very easy to work with but to me very heavy. I also prefer less quilting than is currently popular, part of that is personal taste and part of it is ability -- I just don't think in that way. We have some great quilters here, however, who can do miraculous things with top by the glory of their work.
I decided as a senior in high school that I wanted to quilt, I don't come from a family of quilters. It was just something I wanted to do and have been doing it for some 40 years now, but I am always learning and improving. I'm self taught and unfortunately have learned many hard lessons I am willing to share or commiserate with.
So it's your first quilt and full of things to learn. Have fun along the way. I've gotten close but I've never had a perfect quilt, there is always a problem or something I would change, even if no one knows/sees them but me. Other than having fun, I think "there's always next time!" are the best advice I have
