In my first contest, how many problems do I have to get right in order to go straight to expert level? Or should I just solve one problem and from then get my ranking high. Also, how do I get my ranking high? Do I have to solve a lot of problems in a contest, or do some hacking? For contribution, I just wanted to know what the meaning of it is. Does it affect anything? I only just started this website so I'm not really sure... :)
Play dota 2 and CS:GO and sometimes solve 1-2 problems in one day.
Your rating changes based on your ranking in contests. Generally solving div2ABC in a contest is enough to get you into expert. Practice does not affect rating, but does help you improve your skills so you can improve your rating.
Contribution is some sort of score (I don't know how its calculated) that provides a measure of how many upvotes you have gotten, and is pretty useless other than to boost your self esteem and brag or something. It's pretty much Internet Points or Reddit Karma, but on CF.
Thanks a lot for the help. I guess I shouldn't really care about my contribution. I better practice a lot more.