Hi! So, I used to have the same problem. I downloaded tiktok, even tho I wasn't allowed. I recommend talking abt it to your parents, maybe negotiating a bit. If they have made it clear they really don't want you on it, I wouldn't download it, but if you really wanna download it, here's what to do:
Don't. Share. Personal. Info. Only gender, age and interests. No other social media, then literally anyone has access to it.
Depends on your age. I'd say 10+ since it's a 12+ app, and there are some weird, inappropriate things on there.
Don't download it unless you REALLY want to, but your parents will find out eventually (Trust me, it happened to me, but we came up with a deal and I still have it.)
PLEASE BE SAFE