The question is too broad.

Some more detail would help you get what your looking for.

Are you primarily interested in WWII armor? Allied? German?

In terms of paints, acrylic or enamel?

I've been using acrylic exclusively for about 15 years now and consider it better than enamel in almost all aspects, but mainly cleanup from airbrushing. I've been using Iwatas for 30 years now and if I was starting, I'd first ask where and how are you painting. If you're spraying without a booth, enamels are not a good choice and even ether based acrylics like Tamiya aren't the best idea.

Vallejo offers an amazing paint with great colors for armor and there are similar companies from Spain that nice color lines too. Vallejo should be readily available in most hobby shops and certainly online everywhere. Vallejo offers Panzer Aces sets, which include highlight and shadowing shades, but those are generally geared towards uniforms. They also have tinted primers for all the major armies' armor. You can get nuts with matching RLM and Federal colors.

Again, no there is no basic set, even which theatre in Europe and time of the war will have a different color scheme.