The beginning of the game for Sea of Stars will be a lot of storytelling, to set up the world and characters. When you begin a New Game, you will be asked to choose a leading character, from the two main characters. This doesn’t actually have any bearing on the story, nor really about the gameplay, so you can pick whichever of the two you want. Also, as mentioned, you will be able to change this later, if you want, so it’s not too big of a deal.
After the introductory cutscenes, you will be in control of your character on the Mountain Trail. The other character will run off to do some searching, leaving you alone. As soon as you attempt to strike off on your own search for a camping site, you will be confronted with an enemy, a Wanderer. This will be your first encounter in the game, where you will only be able to use the Attack command. Although you shouldn’t really know anything about the battle system at this point, just choose to attack the enemy and that’s it.
Defeat the enemy, then carry on to the northeast. Press the X (PS)/ A (Xbox)/B (Switch) when near a ledge to climb it, which will be something you do a lot of during the course of the game. Cross the bridge and continue with the ledges, ignoring the enemy you see jumping around on the side. After crossing the second bridge, you will now be fighting that enemy, a Rochevre. Proceed with the first attack, then you’ll be introduced to Skills. In this case, use the highlighted skill (Crescent Arc for Valere and Sunball for Zale), not worrying about anything else and just using the skill.
Once you’ve dealt with the enemy, walk over to the brown thing on the edge of the cliff and press the button shown to kick the ladder to the ground. Drop down the rope ladder and return to where you started, opting to go left this time. Follow the trail and you will eventually reach an opening, leading to some small ledges you have to shimmy across to reach the top. In the opening here, you will encounter a Luslug, and have access to all your attacks. Again, don’t worry about doing anything extra and just do whatever you want to the beast.
Upon defeating it, head through the opening to the south and then continue to the right, jumping across the gaps (same button as climbing ledges) and eventually reaching the campfire with your other party member. Some more conversation will happen, then you’ll get to experience a lengthy flashback.