As far as TTRPGs, I started with solo books - Choose Your Own Adventure and the like, where you just decide which page to turn to; then Fighting Fantasy etc, where you roll dice to fight monsters, inventory (sometimes) matters, etc. By this point I'd heard of D&D but didn't know anyone who played, & couldn't have afforded it anyway. But I found Dragon Warriors, which was originally published as a series of novel-sized paperbacks. I had one friend who was interested, so we'd take turns GMing & playing a whole party. I don't remember the mechanics.