Unsure how to log in and start applying a theme once dreamhost is set up

I’m new to creating a website. I have dreamhost hosting my domain name and wanted to use wordpress to fit out my site. I don’t know where to go from here and how and where to go in to start applying a theme to my website. My website domain is http://www.studiojtv.com but I don’t know where I’m supposed to log in to start putting it together!! Help!