There are no one-word answers to your questions. However, you can learn everything from scratch by doing a simple search on Google. CPA marketing is one of the most competitive and toughest fields. You need patience, dedication, creative skills, and last but not least, a huge capital (If you can't drive free traffic).
It'll take at least six months to become familiar with all the basic concepts of CPA. You must be ready to lose thousands of dollars, in the beginning, to learn it properly. I'm talking about paid marketing. There are so many free methods available. Whatever method you try, you need a proper understanding of CPA before you start diving into it. All the best.