Did you kinda know beforehand that it's something you're interested in? (If it is, but I'm taking a "wild" guess here that you are, seeing as we're on Lemmy).
Didn't have one till I was 15, and that was pretty late compared to most other families we knew (around 2005). I went from zero interest in computers to the geekiest, most knowledgeable computer nerd of anyone we knew within a year of that. It's like I dove into another universe and never came back, which has both had major pros and cons.
The first experience i had witha pc was my sisters 386sx that she got from school. It cam with a netcom.com floppy that neither of us knew anything about but i plugged it into the drive and got to the splash page before learning that it needed an online connection to complete setup. We didnt have one so it was just a fancy beer coaster until aol came along