As Greece your cavalry isn't good, so use your General's Bodyguard units for this. Your infantry is some of the best there is with Armoured Hoplites. You can produce heaps of these guys and they should help you win battles fairly easily as they're tough and easy to retrain.
Early campaign strategy-wise, it's probably a good idea to try to secure Greece first, taking out Macedon. By the time Macedon is gone you should be at war with the Brutii, so make sure you're prepared for the war that will land near your western settlement in Greece (Apollonia? Can't remember) on turn two or three I think. Athens has a high population and an Academy, so before you go to take it, you can remove all governors except for the settlements you want to grow and enslave the population for a boost if you want. Spartan Hoplites can only be trained in Sparta (maybe Syracuse too, someone else can verify this). Ports are the best thing you can build for economy, and get control of the Colossus as soon as is viable. I did a Greek Campaign a while ago now, but it's linked in my sig if you want to read it. Not sure if there's much that you'll find helpful, but it's worth a try.
Good luck, and have fun!
