You did fine, especially for your first time.

When you get your heat gun be aware that you can burn holes in the covering. If you hold it in one place too long the covering will melt.

The good news is that if that happens or if you punch a hole in the covering accidentaly, Monokote is super simple to patch.

Don't try to make it perfect. I have been doing this for a long time and have airplanes with wrinkles in the wing tips. I just live with it! You have something to be proud of.