Nikaah without witnesses

Q: My question is on the validity of Nikaah. Is the nikaah valid by mere confession between a boy and a girl that they accept each other as husband and wife? without any supplication or dua ?and without anybody's permission? And also what will be the kaffara if they are doing so?

Masturbating

Q: I am 15 years old girl. Alhamdulliah I wear a hijab whenever I go out. My problem is that I masturbate, and I feel extremely guilty about it because I know it's wrong but I still can't stop myself. Whenever I go out even though i'm covered I still want the boys to look at me (I know it's very wrong). Whenever I stand in front of the mirror I think that I'm so pretty. I don't know I really want to get close to Allah but I fail every time. I don't feel like praying, I am always tired. I don't know if it's right to say but I hate myself, I hate the fact that I'm alive. I am nothing but a shame. I really want to get close to Allah. I am so scared every time that what if I die suddenly, Allah is never going to forgive me. I don't even know how to explain all my feelings to you. I hope you understand what I'm trying to say because it's impossible to express my feelings.