Child theme or not?

Hello,
I'm a newbie to WP and Atahualpa, and I want to set up my Atahualpa theme correctly before I start to customize it.

Assuming I want to make a number of customizations to the theme, should I create a child theme so Atahualpa will update with my changes correctly for future updates? If so how? (send me a link to instructions if possible, please)

What's the best way to prevent problems with future updates to the theme?

Thanks!
-Gary