The node I'm talking about here doesn't include the lightning network. Its just the timechain. When there is a disagreement, the devs who are having the spat, typically release a Bitcoin client you can download and install. That an on-chain node and a lightning node have become synonymous makes this so incredibly difficult to talk about.
Simple "spat" you can take part in right now, I'd love to be connected to more peers who have full rbf enabled.
Like the article says, knowing command line or having a special OS or special hardware isn't really needed. Just a computer with some disk space that's turned on and connected to the internet with a GUI program known as Bitcoin core running.