Hello Everyone. This is Aryan here. I am new to this platform. I am finding that the questions here are very nice. I am aware of basic programming concepts. I had the following doubts:

1) What concepts should I learn in-order to be able to solve most of the problems ( what are the important concepts of Competitive Programming)

2) Can anyone recommend the complete track ( in the sense list of problems sorted in basic to advance order) which I should solve to be able to compete in various competitions and get a decent rank

3) Can anyone explain what is div1 what is div2 and what is div3

Thanks a lot in advance. I am 13 years old and so I have a lot of time. So I wants to master my concepts at this beginning stage.