You’ll find yourself in the Planet Fargett automatically as part of the story. Walk to the right a bit for more scenes. Three of your characters (including Millie) will be caught in the process.
After the cutscene, you'll be rescued by the local resistance fighters and taken to their safe house. Once in control, you can now use the facilities in the Safe House. The resistance soldier to the north is a merchant and his inventory of items is complete. At this point, you should be able to get whatever you need.
To the left of the merchant are resistance members that handle Skills. You'll be able to purchase all skills from them, just in case you haven’t purchased them all back in Roak. There's an makeshift inn or sleeping quarters to in the left side of the camp that you can use.
Make your preparations and once ready, exit south to reach the world map. You should save on a separate file if you haven’t done so yet. You can also fight a few battles outside the safe house to test if your party is strong enough to explore in this new area.