How to get more & more xp???

Answer 1

Badges & daily login.....

Answer 2

Just engage more with the app.
But it's not that important,
the thing that important is-
Learn from it, don't be greedy of xp. The more you become physically, the more xp you have (both physically and logically).

Answer 3

Involve in the question and answers discussions, do a lot of challenges, learn a lot. Stay focused and be positive. You'll definitely achieve it.