When I set up a new computer, I install a few things right away.
Now the obvious one is Node.js. But, unfortunately, I'm not that adventurous. So I always install the LTS version.
When I'm working on my own, that's all, but lately, I've been working on projects that need me to install different versions of Node.
Perhaps I'm missing something, but I don't need it as much as I did a few years ago.
Then I install Hyper. I wouldn't say I like how the default terminal looks. Hyper looks way better, but it is also extensible and faster.
I've installed a few extensions, but the only one I find crucial is the extension that lets me use different tabs.
Oh My Zsh
Since I already have Homebrew, I install Oh My Zsh! as I feel they go hand in hand. Oh My Zsh extends what you can do with the terminal with plugins.
For example, you can add aliases or syntax highlighting.
Finally, I install Fig. I have the worst memory, and Fig adds the function to autocomplete, so I don't have to remember everything.
And that's that. There is some overlap in what the extensions do but some other functionalities unique to each.