I'd answer your questions as follows.
  1. Begin at the beginning. Literature that is American starts with a lot of British predisposition but gradually grows into its own kind of voice. Beware the more modern stuff, unless that's your bag. If that's the case, don't worry about American poetry or English. Just slam nouns and verbs together and declare everything meaningless and you will have an advanced degree in no time!
  2. Your second question is ambiguous. Yes, I have a path in mind that I tread. If you mean do I have a path in mind in relation to bullet point 1, then see my comments at 1.
  1. It depends on what your goals are. The parameters of what you have defined here are too wide for me to usefully answer.
The path to follow is something you should all ready have some idea of. Start at the classics. Melville, Hemingway, etc. Even if you don't learn anything valuable there writing-wise, you learn something that defines the culture you have said you wish to understand better. Do that enough, and you will find a piece of literature or work that you "get" as being something iconic--at least to you. That is your first rung on the ladder to literary movement/advancement.