Can someone tell me how to add(parse) contest information in my code editor before submitting to any OJ as it is done in Cp Editor?

Thanks in advance.

Hey! Sorry for this question but i was totally confused which is a better way to practice among A2OJ ladders or Junior Training Sheet or random practice on CodeForces (also if it is the one how to select the problems because even for a single rating range there are more than 100's of problems and by this how do we know that we actually have learned a concept which may be missed in those questions) . You can also tell what worked out for you the best. Once again sorry for this post but i wanted to ask it and couldn't find an answer already on this. Thanks in advance.