Gaffer:
Always be upfront with the GM about your level of knowledge and experience. I doubt it will be a hindrance. We were all new to the hobby at some point. We understand.
What Gaffer said. Everybody starts somewhere, so if you don't know something, just ask.
If you ever decide to run a game, the toolkit here is one of the best I've seen anywhere, but that can wait a while. Find you a game or three, and get your feet wet.
Enjoy!