I have noticed that when playing as the Julii it is best to take as many sea provinces as possible it will greatly improve your Denarii count. Almost imidiatly after taking Caralis move and take palma let this grow as fast as can. then move and take Narbo Martius and Massilia. This way your trade will rise and so will your income. If you feel so inclined you may take Carthage. My advice is to enslave the populance. Because you will have a rebellian on your hands faster than you can breathe.Then if all goes well you move to the west and take anyother sea provinces. once you've compleated that build up your armies and invade in any order you want.