Installing and upgrading help

Hello there:
I picked up on Moodle via BlueHost, which allows you to auto-install the program through its individual Control Panel pages using Fantastico.
In any case, I'm having a severe problem with the program now. In an earlier install, I checked the box for Clam AV scans of uploaded files, not knowing what the heck Clam AV was or, more accurately, that I apparently needed to have Linux and a server of my own to use it. (Well, I have Linux, but BlueHost operates the server I use.)
Now, on that first install, I had trouble getting Moodle to stop using a previously used image to go beside my name on discussions. I'd had that one set up under "raymikell.com/class." Given that this wasn't working, I tried a new installation under "raymikell.com/classes." And here's what happened: Moodle stopped allowing new users to sign up, and sent me "Clam AV notification" notices every time someone tried.
In the meantime, I've gone back to using "raymikell.com/class" but am at the point on giving up on this software if I can't get some answers soon. Ridiculous errors such as this make me look bad in front of my students. It shouldn't be this hard!
Thanks for your time. I'd appreciate any assistance you could provide.
Ray