1st time buyer?

i am looking at buying a house, and know nothing about the process. i am not exactly sure about credit score, but i know i don't have anything good or bad on my credit. i don't really have a down payment. i was actually not looking for buying one at this time, just found a great deal, and i would like to get any info i can on how to go about doing this. i am meeting w/ the realtor in a few days to discuss the home. i don't even know what questions to ask, what i will need, or how to go about any of this. can anyone help me?!?!?