There is a simple answer to all your questions: Professional paint store.
Whether its Benjamin Moore, Sherwin Williams, Kelley Moore or whatever, as long as their one and only business is paint, they want and NEED you to succeed and to return. So that is where you go for both supplies and paint. Not only are they going to answer your questions and provide the best products, you need only ask for a preferred customer discount, and 20% off is yours. So the best materials, advice and price.
The minor chipped spots require a small container of drywall compound or spackling and a piece of sanding screen, the painting supplies should be pretty straight forward, edging tools like a brush or pad, and a roller to do the big areas; drop cloths and good quality paint. The store will even help you estimate coverage. Give it a try, and good luck.