The hardest part of sewing is the part I told you: figuring out where to sew and why. Second hardest is getting the thread in the needle.
Your first sewing lines will look like crap, and that's okay, because they're on the inside where nobody can see them. That's why we turned the skirt inside out first. =)
Oh, and if you want to lean into the jank, you can use a stapler instead. Does the exact same thing as sewing.
Definitely not on copyright grounds, since almost all state flags (except Georgia, Mississippi, and soon to be Utah) are old enough to have entered the public domain.