Like some have said, D&D isn’t the ideal system or super beginner friendly.
But, it’s the game that so many people I know started with, and most were 12-14 when they just bought the books and dove in. And that was second edition which was much more arcane than the current edition. If you accept that you will accidentally be breaking the rules constantly as you learn then you’re in the right headspace.
I started with White Wolf games when I was 16, and I bought the pure fluff supplements before I bought any rule books. I still feel like it’s one of the easiest systems to make a character in but I’m probably pretty biased.
Fiasco might actually be a good starting game, or Lasers and Feelings. These are designed to be one shot games with more minimal rules. There are a number of quick games like that which we use as pick up games when someone misses our regular game. Tactical Waifu and Everybody is John are quick too but much weirder.
We got my friend’s mother to play Fiasco with us at my last birthday. She’d never played an RPG before but had a great time with it.
