[MegaTrain]

Yes, either use another colony ship or build a dedicated population transport ship with cargo containers.

Use the "transfer cargo" button (two arrows) to move some people from your homeworld to the ship, then send the ship to the planet. Don't use the colonize button (it couldn't anyway--you'd never lose a second colony ship) then use the transfer cargo button again.

You should be able to tell if a ship has people on it. It will have a little person icon when you click on it.

Cool idea: load a colony ship, send it to the planet, drop off just HALF the people, then use the ship to colonize another close-by planet.

And WELCOME TO THE GAME!!