Installing Git isn't always obvious when it's the first time you've done it. I've found that it's best to use Google to search for "installing git", and typically I got the answers I needed after reading 2 or 3 pages. Search YouTube for similar things and watch a couple videos/people actually go through the motions. It can be different based on which OS you use and where you download it from.
Especially if you're newer to using Git and don't have specific needs, you are likely to be quite safe going along with all of the default Git install settings. Go through the 7 or 8 screens with the default settings, and find/enjoy some of the well-written tutorials or YouTube videos out there, too. I remember thinking similar thoughts to you, and it feels a bit overwhelming, but I realized I was over-complicating it for myself.
Since the install process, and peoples' unique needs, can vary so much and since it's not truly part of the framework (but is obviously necessary), the Adapt guides don't get into the details here.