Writing Characters

I currently writing a YA, Fantasy, Thriller, Romance Novel and I need help with the characters and their personalities.
The main character is Torah Behnam, he is 17, his MBTI is ENTP, he is witty, funny, extraverted, outgoing, and blunt.
His parents are Adelfa and Ahmed. He is mixed raced. In Our World he'd be a mixed race between Persian and Phillipian. (Sorry if I didn't spell that right)
The other main character is Dyla Mandela she is 15.
Her MBTI is INFJ, she is quiet, reserved, introverted, has anxiety, generally nice but if you mess with her friends she is a beast!
In our world she'd be considered African American she is a lighter shade though.
I have the layout pretty much set but what I really need help with is with the dwarves and the bad guys.
I also need help with the names
So Torah is from the kingdom of cyrus and everyone elses kingdom/tribe I have no name
Dyla is from a african inspired tribe but I have no name
And I got no ideas for the villian or her kingdom or for the dwarves.
I would love some help