For anyone who is good with creative writing, How would you write a character being told by their parents that they are a supernatural?

There's no specific way to write a character. This question is completely up to you.

Just ask yourself:

What kind of supernatural?

Can they read minds?

Can they shape-shift?

You make the character.

It can be a 13 year old boy who doesn't even notice anything strange about himself or a 23 year old woman who's been wondering why she can hear other people's thoughts.