Okay 1) tell your agent to manage troops and ressources 2) as soon as the game starts pause and look on your different planets and send those who have a reasonable diplomacy rating (above 60) to go and start converting planets to your cause. 3) if you are the rebels your base will be on the outer rim and have some transports posted at it. Use these to go and colonise sectors on the rim. Also try and specialise some outer rim planets in construction of troops, facilites and shipyards. There that sould help you start up.