Are you just beginning to play this game, Silver? What I would recommend to you in that case is to start off playing single player with Easy AI and then go to Normal and keep playing single player until you can beat a Hard AI. Then you may head into the realm of Sins multiplayer. From what I hear it is pretty rough for beginners and it is much easier to start Sins with the single player and become skilled at that and then head on to multiplayer.
I am not really a multiplayer person, nor do I play TEC much, so I am sorry but I cannot help you much in terms of strategies. What might really help is just flipping through the digital manual and reading the unit and structure descriptions to discover what units are good at what and what abilities they have and so on. Other then that, I recommend you check on this forum frequently to find out what strategies are the most effective.
By the way, which faction do you choose, TEC Rebels or Loyalists (TR and TL respectively on these forums)? I might have a few tips here and there but I am sure some hardcore player would be far more helpful than I.
