It’s totally possible that pedophiles and abuses are using tiktok and Instagram to groom children, but most of the time it’s someone that the child knows that actually does the abuse:

“ A common myth is that child sexual abuse is perpetrated by strangers and pedophiles. But most people who sexually abuse children are our friends, partners, family members, and community members. About 93 percent of children who are victims of sexual abuse know their abuseriii. Less than 10 percent of sexually abused children are abused by a stranger.” https://www.ywca.org/wp-content/uploads/WWV-CSA-Fact-Sheet-F...

So I’d not freak out too much if your kid searches for something really weird, because we all did that as kids.