Help-Transfer Template

Hello. Sorry if this question is dumb but I’m new to all this and need help. I just signed up with wordpress and I have Host Gator for hosting three blogs I’m working on. I used Artisteer template software to create a template for one of my sites but don’t know how to import to wordpress. Someone on Artisteer told me I need FTP account so I downloaded Core FTP program thru Host Gator but I have no idea what I’m suppossed to do with it. Can anyone help, I would greatly appreicate it.