Do you want to learn how to program a game? Or do you want to learn how to "make" a game? Those are two different tools. The later, Unity is great. The former? No real way, but I'd suggest monogame.both?
i "know" how to program but i wouldn't say i'm great at it. I learned on C and Basic and these days I read (but don't write) C#. Like i said, i kind of just want to get an appreciation for it so making a very simple game would be fun.
a long, long time ago i invented a card game. i had thoughts that might be a good place to start as it is probably a lot less ambitious.
i just don't know what i don't know so i really have no idea how to start "eating this whale".