So I'm new to dnd and I have some characters and joined a couple of campaigns and I have a character named Kingdor Raiser, his real name being Faren Sare, a 14-year-old teifling Bard/soon to be a wizard that takes place in a low magic setting. The story is this

'Faren was really young when he went missing, not really knowing or remembering his parents or what they looked like since his memories of them were erased. Only having a weird Music Box that he had when he was taken. From what he knows he was instead raised by a Hag named Morphilsa. Raising the boy to do her bidding and using him as a sort of experiment for magical purposes. Because the Hag never really let him leave the house and the area he can only imagine what the world is like from books and studies he finds and was allowed to read. Learning about instruments that he soon learned how to play and when given a break from doing things would try to practice singing and so on. Later developing magic due to the hags experiment that was a bit more dangerous than usual causing a burning scare on his right hand. This was a breaking point for Faren as the hag did start to use him more on his magic, making his scare even worse and more painful. After this he decided to leave not wanting to deal with the pain anymore but unaware that the hag was still keeping tabs on him, causing him to do bad things and have evil thoughts as he tries to survive the world he thinks what it was in the books.'

Later in the story, he wanted to leave since he was cooped up in the house and was tired of doing these little experiments for his mom that did end up in pain so he left of course with his mother keeping an eye on him from a far distance.

This is where my question begins one thing I know is that he would not know much about the world and in this one nothing is the same since the world is collapsed and he only read books about the old world. 

Now the question is (because I and the dm did not think about this until recently) would he have grown to eat humanoids since that's basically a hags diet and so he would be fine with eating people but can still eat normal food?

There's a lot of things I don't know and probably some more questions that I didn't think about yet so I ask for help with this please and thank you.

I guess it's flavour. Does he embrace the darkness of the hags? Or reject their cruelty?

Well sort of, only because he was raised this way and was influenced like this, so I assume someone raised in these types of conditions would find it normal. Thing is he doesn't really care for it, and could still do good things just doesn't have a moral compass.

I would say look at the table for shadow sorcerer if you can find it ( it's from the book xanathars guide to everything). That should help with the quirks and personality of your character. 

Yeah I will try that, thank you.