if you are collective, in order to start off you need that initial supply of money in order to support a fleet and capture colonies and plunder, you will need to focus on making food
and a good surplus of it
then sell the food one the market, and research all of your ship technology, and make more food, and sell it
then, build up a fleet, and look for easy targets (lots of planets low power, offline is a good hint they arent defended either)
then maintain a good buffer of colonies that make some food for you to sell when not fighting, and just keep on capturing and plundering, and hope you dont hit a bad losing streak