Carrie,
When drum brakes squeak, it usually just means they have a build up of crud inside. That said, moped brakes a really easy to take apart, you should open them up and look at them. Gives you an opportunity to check and lube the wheel bearings too.
You may as well ckeck the spokes too and the steering head bearings and the swingarm bearings....
Excuse me, it's spring :-)
Ron