Everybody is there to have some fun, not to get insulted. Be nice, watch your language, play fair and obey the rules of the server you're on. The network speed determines how fast you are fed the information from the game server, and therefore how fast you see your opponents and how quickly you can react to them. Usually, this is called Ping time. Ping means a signal is being sent between your PC and the server and measured how fast the response comes back to you in milliseconds.
Lower numbers are better because it means the signal travels faster.
If you use a regular 56k phone modem, you probably will get a ping around 150-250, depending on your connection. Anything over 400 is considered unplayable. Enjoy the game Online gaming is fun. Don't be intimidated by the variety of games, different servers and types of games. Explore, try out several and find out what you like best.