I had a computer with Civ, Exterminator and Dyna Blaster before I could read. I was terrible at all of them, but it didn't stop me. Through trial and error I figured out how to train units so I'd spam basic soldiers and fight barbarians until another civilisation inevitably found & destroyed me.

It wasn't the very first (that was either Sokoban or The Games: Winter Challenge), but it was definitely within the first dozen or so games I ever played.

I didn't even understand English for the most part back then, but still somehow steamrolled the whole world with my despotic civilisation (I didn't know you could change governments). I remember half of my cities falling into civil disorder every single turn late game, and all the buildings I made kept getting sold off because I had no money (I had no idea money was a thing in the game). But apparently the easiest difficulty is easy enough to still beat the game like that.

I'm a big fan of stellaris and I played a bit of Civ 5.
Civ 6 is the most impenatrable thing I've ever played, even after the tutorial it still feels like I've been shown how to use a hammer and then immediately asked to build the Taj Mahal.

I mean, it's well known enough nowadays that I can imagine some people starting with that.

That said, I think for beginning gamers, some of the classics like Pac-Man, Pong, etc. would be more suited. Or maybe Pokémon, oldschool Runescape...