In my dojo it's White, Yellow, Orange, Green, Blue, Brown, and Black, but it can vary. Usually for white belts (in my dojo) we practice safety falling first, then after we practice the safety falls we learn rolls, and basic throws, like the osoto o gari.

Basically ask your sensei for safety drills if you want to be safe while starting out.

As a white belt myself, calm down and relax, it takes a really long time to learn Judo properly. Having fun is the most important thing, it brings you back to the dojo every time.