To be fair, Civ 7 might be the worst entry for roleplay, which makes me sad. Mostly because of the age reset. But it's still doable!
First thing I do is to ignore every kind of victory condition (or turning them off if possible). Then you just take actions that you think would fit better with the kind of empire you are running, or the kind of ruler you wish to be. And don't do things that would ago against your vision, even if it means you're not playing optimally.
For example, not taking over that one lone city or city-state when you're playing a benevolent ruler, even though taking that city might give your empire good things that will help you in the long run. Or starting a war against an empire that you can easily take over but you limit yourself to a border skirmish and only kill units.
Colonizing a one tile island in an ocean between 2 continents, which will cause a negative modifier to your overal numbers. But you can pretend it's a lookout post, or forward operating base. And then of course actually use it as one. Stuff like that!
The only limit is your imagination most of the times. I think it's a lot of fun, and a game ends when you feel it's done. Not by scoring some arbitrary number of points of whatever.
For me it was the chariot icon in Civ 1 that I couldn't interpret. It looked like a guy who was about to be shot out of a cannon lol I was around the same age.