Hey Josh & welcome to the forum!
In order to make body parts such as hands, head, faces etc. you need to start to learn about a “Sculpting” in Blender. There’s a various video tutorials about that on YouTube. You can start by watching very simple ones like “how to make a low poly character” or “how to make a simple bunny”.
Sculpting, if in a few words, is a very huge topic to discuss about. There’s a lot of tricks, ways to how to do this or that. So all I can say is be patient and don’t give up.
There’s come official documentation about sculpting:
https://docs.blender.org/manual/en/latest/sculpt_paint/sculpting/index.html
Me, I am not a professional at sculpting. Here you check out some of my sculpting works:
Bunny,
Penguin
It was kinda easy to make them.
Hope it helps you
Cheers!