You can find the android ver you have by going to menu>settings>about phone. I think it is listed under firmware version. Since you have a Droid X I will assume you are running 2.1 as 2.2 has not been updated for any of the Droids on VZW.
Fair warning "rooting" can open a whole new experience for the phone, but it is not for everyone. Read up as much as you can, and be sure you are completely comfortable before doing it. There are ppl here that can help if you have questions. Otherwise you can always just patiently wait for VZW to release 2.2