I’m new to this too and I’m stuck at about the same point. But I believe once you run the mini web server command (python3 -m http.server 80). It should say: Serving HTTP on 0.0.0.0 port 80 (http://0.0.0.0:80/) …
It should be stuck here because the server is now running.
To check go to your web browser and type in 0.0.0.0, or whatever ip address it has for you and you should see the files from the folder where ever you started the server from.