I had a lot of requests for the intro Dungeons and Dragons powerpoint I made for my players, and while the one I sent them was way more involved and specific than this, I think this will give you a good general overview of the rules. The most important rule, of course, is that all the rules in the game are guidelines, and the ones that are actively getting in the way of your fun can absolutely be dropped.
If there’s interest in this, I’ll adapt my race/class powerpoint in a similar way.
As someone who first picked up the AD&D player’s handbook from a comic book store like 14 years ago, futzed around a bit in college, and then dropped it for years and years, it’s amazing to be revisiting the game again and seeing so much enthusiasm and creativity in the community.
Have fun playing!