Civilian ships aren't built at all until you have at least one colony, so subsidizing them now will just go to hookers and blow dividends.(1) Just marking a planet as colonized isn't enough, either. Shipping 1-30 Inf(2) is sufficient to start things, but you must have a freighter of your own to do this. A ship order by itself isn't enough.
In short, you are boned.
1) Only subsidize if they have less than $2000. Do not get them wet. Do not expose them to sunlight. Do not feed them after midnight.
2) 1 inf if they build a freighter first, as you can then hire the rest. 20 inf if they build a small colonizer first, 30 if they build a large one. The colony must have more infrastructure than is needed for a full load of people before a colonizer will actually deliver people the first time. Whether they build a colonizer or a freighter first is random.