As usual, the very first skill a new colony needs is a
terraformer farmer agricultural specialist, who can get more food to grow.
From the comments, I gather that deciduous trees (which lose their leaves), worms to improve the soil, and a way to shift from animal-dependent to plant-dependent methods.
Still no internet, so I won’t be going. (And I totally lack the skill sets needed!)
The Traveller applications should be easy to spot.