If you have the stock ROM, you are odexed. Go to Settings, About Phone and scroll down to see what the Build Number is (EK02 or EL29). Most of the custom ROMs are deodex.
Just keep reading and getting familiar with the phone before you jump in. qbking77 has a
YouTube channel for the Epic Touch 4G that has all the how to on video. I'm sure there is a video showing how to install the Hotspot hack and clockwork mod in there somewhere. Like I said, get familiar with the phone before you start messing with it. Have fun!