Talking build social network app

hello every one
I want to build a social network app for my college and I want the program have a database of the id number for student and I want the app have a profile for every one and wall like the facebook and they can upload pictures and videos and send private message text and voice message and the app have a groups , that is all in my brain ^_^ right now . but I don't have any idea for programing android app for that I come to my second home and my second family ( XDA DEVELOPERS ) , can any one help me and tell me from where to start , thank you very much for trying to help me