Political Party Affiliation Question.?

So, I have been a registered voter since I turned 18. Just recently in a couple of my college courses, we have examined political parties and I have shown some interest in joining a party. My question is, what does each party stand for and how can I go about choosing the party that I would best like? I read countless articles and websites, but I just get even more lost. I want to know what the parties stand for and what they believe in.