No advise for the test to be honest other than have fun and don't be afraid to go a little out of your comfort zone when practicing for the test. Not too far, but doing so a little bit will help you to understand that you're more in control than you think you are. It's easy to feel like the bike's in control when you're first starting out, but don't worry, it gets much easier
as for the fall, that's why it's a beginner's bike! These bikes are tough though. I think every EX250 has a chip on it like that, mine does and so does anyone else's that I know of that has one. You can always wet sand the spot and paint it if it bothers you too much.
The rims look nice! Good luck on the MSF course