Smile hey there :)

Hey everyone, i'm new here so I may aswell post an intro to me.
I'm Tom, 17, Aussie, currently unemployed and not in school.
I'm interested in Android modding/hacking, and just wanted more of an insight, i've looked at alot of threads on here and thought "hey, I should join" and I did
Anyway, 3 questions.
1. How do I root my nexus 7 (2012) simply? (Tried towelroot)
2. Is there any way to edit .obb files? Preferably on an android device.
3. What would be the best program for modding in general?

Thankyou for your time, and I hope I fit right in :3