you are in the awkward phase of the game where progress, I feel, is at it's hardest.
The way I see it there are two strategies where you stand and you have mostly decided.
You could be an explorer or a Pirate,
An explorer will get more resources by finding new planets and building new colony. You need transporters to bring resources to the planet, once found, so work on that soon.
A Pirate will get ahead by looting other nearby planets. To do this you need to build up some ships.
Most people are exploring from what I can tell. I am not an expert, just started exploring myself but if you have not seen it yet check this resource for looking around your planet.