The tablet should automatically notify you of an update. It will show by the clock in the lower right hand corner.
If it is NOT there, go to Settings - About - Check for update, then check the notifications again.
As far as the dock, it should still be able to be registered. I have not been on their site in a while, but you can always call tech support and ask them how and where to do it.
For A/V, if you are worried check out the AVG in the Play Store. It does a pretty good job, however viruses/malware on Android tend to be few and far between, unless you are installing battery saver and wallpaper apps.