@geo i can only suggest that for the base system setup, google is your friend… you can find articles about just about anything…
as for MagicMirror… yeh, there is a lot to learn… each module creator gets to specify their own config setup beyond the minimum…
I see that Mykle has posted in your other topic a link to his very good doc.
keep coming back, ask specific questions and I am sure there is someone who can help you