First Time WP User

Good Morning. I’ve just started using WP and hoping someone may be able to help me. 1.) WordPress Back end is PAINFULLY SLOW when making changes. Using Mac w/Mountain Lion, Fatcow as a host and they say use a cache plug in but was using WP Super Cache and this didn’t help. Same response on different computers and different servers. 2.) Even after clearing the cache in Firefox and reinstalling the Titan Premium Photography Theme twice (to correct issues I created) Firefox still won’t totally update all changes I make to my site. However, I can see changes when I use Safari. Deleted Firefox add-on Firebug and no difference. Not sure if I need to reinstall firefox. My site is http://www.melgattisphoto.com. Currently I don’t have any images or plugin’s activated. Just trying to get the basics right before going on and wondering if I have messed up code somewhere.
Thanks. Mel