i know that everyone pushes that fandom is a safe place, and yes, usually it is. for your identity, but fandom is still the internet and the internet is never a safe place.
the internet is full of creeps, just because someone is interested in the same things as you does not mean that theyre not a threat, just because someone is queer doesn't mean that theyre not a threat to you.
this is coming from someone who got groomed for two years by another minor (though much older) within the lgbtq community because i, as a 12 year old, assumed that she was safe.
i have had people like 11/12/13 tell me that they saw my pronouns and assumed im safe. i may be. not every non-binary 17 year old on the internet is.
being friends with another minor, as a minor, may not seem like a big deal but the emotional maturity at 16/17/18 is vastly different from 11-15, and no matter how mature you consider yourself, you cant race ahead of your brain development.
you never know any true information about anyone on the internet, just what they want you to know. makinh friends with in your age range is the safest bet, but if youre forming other friendships, never rush into them, never give your address/full birthname/any sort of information that can be traced back to you.
also, people do often pose on the internet to entice and draw in people, dont let yourself fall for it.
internet security is important.
and the moment somebody gives off creep vibes, ghost and block. no need to confront them, no need to do anything. ghost and block. then inform a trusted adult.