apple id forgotten

Hello my name is Ahmed and I'm from Ghana .apple products are not  very common in my country so difficulties such as Apple ID lost is very difficult to solve .my sister was in Saudi Arabia up until 4 months ago when she came back .she brought with her and iPhone 5s which she gave me but the problem is that she doesn't remember the Apple ID or the password for the Apple account which makes it very difficult to login and she bought the phone second hand from someone else over there and now I am very confused on how to proceed what are my options I would like to know please.

thank you

[Email Edited by Moderator]