Bitcoin node running, questions about learning Linux and system engineering thru Umbrel

Bitcoiner here, but also system engineering n00b. I want to learn more about Linux and coding and I plan to use the Raspberry Pi as a playground (it only runs Bitcoin node, without connection to any wallets or lightning nodes just to be safe)

Please halp:

I have a hard time grokking the difference between Raspberry Pi OS and Umbrel. Most tutorials assume Raspberry OS is installed and as a systems virgin I’m not sure how to translate that.

Some more concrete questions:

  1. How do I get command line access to the device? Are there SSH client apps I am missing or do I need to SSH into the device via Terminal on Mac?
  2. I did find a terminal in the VS code app. Is this another Linux distribution or how does it relate to the Raspberry Pi itself? I tried the ifconfig command but just got the “command not found” response…
  3. I am trying to deploy a very simple Python app on my Raspberry Pi (a boy’s name battler game as a surprise for my pregnant girlfriend).

To do that, I installed virtualenv in VS Code and then installed Flask in the virtual environment (I called it env). Finally I wrote a simple python program to test if it works:

from flask import Flask
app = Flask(name)
def index():
return ‘hello world’
if name == “main”:‘’, port=5000, debug=True)

In the terminal, I ran the following command: flask run and it returns:

I then ran following command in the terminal: flask run --host= --port=5000

And it now tells me:

When I try to access the app via nothing happens…

All help appreciated (be it answers to my generic or specific questions, or links to learning resources)