If you can fix a car you can build an AR.
It is not brain surgery. If the upper is already assembled, you don't even need any special tools, though a roll pin punch is nice.
For your first AR, I recommend a complete Bushmaster. Chrome lined barrel, quality, warranty, etc. Don't start off cheap, since you get what you pay for, and not too many of us are willing to start off with a headache.
My $.02