Hi jt fleming!
I'm sure the x10hosting forums can guide you in making your first site.
The first step is to go into your cPanel (stand for control panel) which you can access by going to x10hosting.com/portal and logging in, then choose "Access cPanel".
Then choose the File Manager and go to the folder labeled "public_html".
That is where you can upload your hoem page and files associated with it. One newbie mistake I see very often is they call their homepage "home.htm" or "homepage.htm". It has to be called either "index.htm", "index.html" or "index.php" in order for the server to recognize it as a homepage.
Once you have your index page uploaded, check out your site at it's address. If it isn't working, it should be within 48 hours of registration!