Personally, I would go with a built computer from someone local, if you can afford it. that is how I got my first computer. Bought it from a small, local guy who has a small computer shop. Having a local place to take it to for help or service (and most will warranty their work and of course the hardware generally all has a warranty) is wonderful. Just unhook the tower, take it to the guy.....I generally stood right there as he worked on it and was able to learn some things.

Then when he was done, I just picked it up and brought it home.

No weeks of waiting for shipping back and forth. I was also able to upgrade components as I got the money, and have been able to keep my computer current for going on 8 years now. Pretty much everything is new except for the tower, lol. But I did it a piece at a time as I could afford it.
A local place depends on word of mouth, so they will go out of their way to make you happy and to take care of you.