Are you really pissed over a christmas gift? If my parents gave me a mac book, i would be happy. Your parents also must have put a lot of thought into giving you this gift, and you complain about it? If you sell it, think of how they will fell if my kid sold my christmas gift that i spent a lot of money on and thought he would like. Most people can barely afford computers, let alone a mac book...
If i were you OP, i would be great full that they got it for you and just do what you can do on it, you can play blockland and steam has a mac os platform