Whatever happened to FTP

I grew up using CMSes like GreyMatter and Movable Type where you just had to change a couple of settings, upload the install files to your server via FTP, maybe mess with the cPanel, and off you go. A lot of CMSes nowadays want you to use the command line and/or start Git and I feel out of my depth. Halp? After years of multiple sites across multiple SquareSpace/etc accounts, I want to consolidate them into one space with subdomains for different projects. I was deep in Early 2000s Teen Girl Internet, where people would set up accounts on Dreamhost and you can set up your own sites on their subdomains using GreyMatter or Movable Type or something and change the design every few months with basic HTML/CSS. A couple of decades later I'm looking at CMS options and so many of them have instructions that make me feel like Old Man Yelling At Cloud, like they were written for professional developers and not Current Me or Teen Me.

I'm familiar with using the command line for things that involve my own computer. I am less certain about how that's meant to work if you're trying to install something on some server space you rented off Dreamhost or something. "Just type 'install X'!" - wouldn't that just install things on my own computer? How do you connect your command line/terminal to this server space?

I've also used GitHub for my own projects. But again, when it becomes the first step for something that involves a server that isn't yours, my brain bluescreens.

Is there some primary step I'm missing? Something super obvious that makes everything else click? Or are things really more complicated now? How do I install and manage a CMS myself and make it look pretty???

(Please don't suggest WordPress, I have a long-standing grudge against Automattic. TextPattern seems the closest to what I'm used to install wise but other recs are useful, especially ones that let you have a layout that isn't just a stack of text.)