How to paint? ...
Answers: Since you aren't at all specific; It might be difficult to insist on here.
I won't even bother to assume what or where.
PREP! Before any profession; might be the more important segment of any job. After applying multiple thousands of gallons of paint; I'd prefer to spend hours prepping a livelihood; than to OOOPS a job.
Latex/ Oils/ Epoxy are adjectives different formulations but are often applied surrounded by the same bearing. There are different sheen levels that might denote multiple coats. Different drying times and toxicities to consider. The GOOD or not so good of a profession usually happens through experience; but indubitably there are guides within the form of books; videos; links here; demonstration workshops at the Big Box stores; etc.
Spray sculpture is another technique; with methods entirely separate from brush and roll.
Exterior/ Interior require somewhat different technique applied.
More detail would be helpful; and near all due respect even yahoo suggests that.
Steven Wolf
First you verbs the dust off the baseboards and after you use a brush to cut in .Starting at the top close to the ceiling on the wall.Also on bottom ,Cut the corner of the walls also Then you use a roller to roll your wall the color you want. This consists of a 5 gal. bucket and a metal grid that go in your bucket.A long knob pole with a roller cover.Keep a humid rag handy for any drops you will bring,Also use a drop cloth since you don't know how to paint.(you have to be upright not to have one)I expect i would find someone to do it for you lol