How to play Black ops?

Okk i have posted alot of similar questions and im getting annoyed because im a very bad black ops player with a 0.5 KDR i was hoping if one of you guys could either make a video and post it on youtube about tips and tricks for black ops and leave your channel in the answers box or the other suggestion is to leave a good answer with at least 5 tips to get better at this game eg. guns to use gamemodes to play to level up etc. i play ps3 if anyone wants to play with me send me a MSG