Hello, codeforces community. I've just started CP and I have a couple of questions.

(1) Should I start immediately with contests, learn algorithms if I stumble upon a problem which requires it and uplsolve it or first practice from problemsets on codeforces and then start giving contests?

(2) From where should I learn the algorithms and data structures from?

(3) When should I read the editorial, some people suggest that they look at the editorial when they are 'tired' of the problem or should after half an hour or an hour for difficult problems>

Thank you :D