Don't apply AT ALL.
the OP is a beginner and is getting into indie development. As such, the methods and requirements of AAA development don't really apply.
Seriously people, get out of the mindset that "just because AAA games do it, I must too." This applies to everything, including what engines you use, what languages you use, and whether or not to use regenerating health.
As far as Unity vs UDK goes...
I've always found UnrealEd to be fairly easy to get into, but the Unity editor is also quite trivial to get into as well. They both have some decent tutorials, however I believe the projects that come with unity are both more complete and generally easier to follow. MY recommendation then would be to use Unity.