Hi and welcome. Since chances are you'll be given a passage from a specific text, you might want to check out the vocabulary tool
at the Perseus site, if you haven't already. It lets you list the words from a text in order of frequency so it might be helpful in focusing your efforts. But really, I'd recommend reading as much of it as you can, both because there are all sorts of things that can trip you up even if you know the meaning of all the words individually, and, at least for me, it's easier to pick up vocab through reading (especially the inflected forms) than, say, flashcards or whatnot.
And ask as many questions as you'd like. The Greek forums here are a little quiet lately but there are a bunch of people here that would love the chance to answer questions.