right now the factory os is 4.7.140 and if you want to uprade to a leaked 5.0 OS then you need to download it from these forums and use Desktop Manager to upgrade.
you can download desktop manager from the blackberry.com and go to the beta OS discussion section and do some researching, i personally didnt like it because of battery issues but its some people who loves it, to each is own but just fish around the site youll get use to it.
Is there an update for the tour, and if so is there a way to do it over your device and not have to use a computer??
No official update has come out yet. When one does, you can download the new update right from your phone. All you have to go is go to Options, then click on Advanced Options, then click on Wireless Update. No need to do it from a computer if you dont want to when your able to do it right from the phone.