Outook 2016 / 365? Contacts, Groups, Addresses - the Definitive Guide

I'm using Microsoft 365 and Outlook and no Exchange Server.
I'm trying to simply manage my Contacts or whatever the )(*#&%)(*%& one might call "LISTS OF NAMES AND EMAIL ADDRESSES, ETC."
I have finally decided to just learn how to deal with this mess after all these years.
But how?
What is the definitive or best tutorial that will allow one to figure out what to do?

I see lots of references to "Open the Contacts Folder".  Well, of course, there is none.  What they mean is to "Use the People link at the bottom left and see what opens up".
All I want to do right now is this:
1) start with a CSV files of names and email addresses.
2) Create a Group or email list that I can send emails to the entire group.
3) Create another, etc.

When I create a Group, it doesn't show up anywhere!  arghhhh!