Modeling Humans- Need help! (I'm a beginner)

Hello, creating animations with humans has been on my mind a lot lately, so I decided to search the web on how to model humans…

My results were very complicated, I couldn’t understand some, but I found a short 10 video process on how to model people.

I see that they are making their model based off a picture they had, and I see it had Front views, and side views.

My question is:
On the side view, does the arm just stay the shoulder joint or are we actually drawing the whole arm and hand in the side view?
I feel like this is vital to modeling because I really don’t want to spend tons of time modeling a human and find out I messed up, or didn’t have the arm to model?
Sorry this is kind of hard to explain, I know very little of blender.

For my second question, is there a way to save our model and reuse in other animations?
I plan on making TONS of animations with the same characters, or at least the same protagonist.
I want to be able to continue using a model I’m satisfied with so I don’t model the same human everytime I open Blender.

Sorry , I’m very very new, I’ve only made 1 animation and it was horrible, haha.
If you can, please put it in a very blunt way, or answer my questions the best you can so I can somewhat understand them, thanks!

Do yourself a favour and start learning modelling with something different than with something of the complexity of a human.

Hmm, okay, thanks.