Adding WP to…WP?

Hi guys I’m new to WordPress and having trouble figuring some things out. This has probably been asked before but I need help. I’m working on getting a blog set up on WordPress for a school project. I already have a site set up using the client available in the browser. Unfortunately I need to install adds so I installed the client on my desktop. However I’m confused. I don’t know if or how to connect it to my already existing blog and then how to proceed editing it. Any help getting this figured out or leading me to a place that has answers would be greatly appreciated.

Before anyone asks I did spend some time in the FAQ and didn’t see what I needed. Thanks.