Okay, what is the difference between these 2 questions:

What are the things your friend should know about htis person? What makes him/her interesting?

Please explain the differences between those two questions.

LIke, if I say the character likes chocolate chip cookies and I write it under interesting. Woudn't that also fit under about the character?

Thank you very much.

2 answers

You might tell your friend that the character likes chocolate cookies, if your friend does too. I wouldn't call it interesting, but it might establish a bond with the character. An interesting fact might be that the character has spent a lot of time traveling in Europe.
Things you should know about someone = hot temper; of a particular religion; recently lost a loved one ... etc.

Interesting things are usually positive things, like what you said about choc chip cookies.