I just bought a new bike and some of the questions have been developed. HELP!?

I bought a Diamond Back Sport response to 20-inch disc brakes and at a speed of 24, but the brake disc before starting to show a little rusty when I did not even much wet riding. Also, I do not know whether it is a general problem with bicycles, but my derailleur does not move that much. As if I'm going and I want to be a 7 gear, chain re-6th Procedure. Even my bike chain was uncommon, and they are moving themselves. My problem is to derail and the rust of my discs, because my bike is broken or rust is normal and I just need to adjust the derailleur?

Brake rotor to grow a little rusty if you do not get all the time, but this should not happen in a way that is obvious or a brake problem. This should not be more than just a light coat and almost dusty. If this is the worst, and let the Pit, it probably is a rotor made of cheap low-quality steel. Questions to ask the store you bought it for a replacement if it is so. Less general after the "break" period. Cables stretch and things should be strengthened. Most of the shops Cycling offers a free song from 30 days up. Than this is after 30 days, you'll probably pay for it, if the owner is very cool and the shop is not bad.

Cottonwood Valley bike trail – Blue Diamond, NV