WordPress is the most popular platform today for building websites. You're in good company:
Mostly everything is going to run on is own behind the scenes. The website monitors security, makes daily backups, and updates software by itself and sends me status notifications. I'm happy to add you to the notification list if you like, but mostly they get boring.
Dashboard and admin panel
After you log in you see the dashboard and the admin panel:
The dashboard shows security and backup status, and below that a log of recent activity and a summary of the number of posts and pages. The admin panel to the left is the meat and potatoes of administering WordPress, so let's go through those menu items.
What you're looking at in the screenshot, plus another submenu item that lets you make all the different updates in one place. That's all automatic though.
If you ever need to get a new administrator, make sure you find one who knows WordPress and show them this page and they'll have a pretty good idea how to jump in and take over.
If you want to learn more about site administration yourself, or work directly with Post and Page content, I'll be happy to help you learn.