Not connecting to multiplayer servers and disconnecting from MC hunger games servers, not allowing me to open chests or damage players yet not a spectator.

I really wish I could play online servers ( especially since 1.6 ). I have watched MC Hunger Games on YouTube and I wish I could play them without any bugs and connection errors. I want to figure out the problem if it's something to do with Java, programs, etc. Please let me know what I can do to solve the problem.