converting a site to wordpress

I want to convert a site to wordpress. This is new to me and I don’t really know what instructions to follow. Here’s what I’ve done so far. My original site is on the root of my domain. I installed new WP blog using fantastico and have got it to where I’m ready to make it public. I logged in to the new WP blog and changed WordPress address and Blog address. The next step is to move WP core files to the new locn which I don’t know how to do. Do I log into cpanel or do it from filezilla? I also have 3 addon WP domains. Do I do anything with them?

I would appreciate any help anyone can offer.

Thanks