Why is it only you and Shadowheart?
By the time you get to the goblin camp, you should have encountered Asterion, Gale, Wyll, and Lae'zel.
Companion Locations
The first two are near the crashed Nautiloid (tentacle ship), before the goblin fight in front of the grove. Asterion to the west of the ship, Gale to the east at the fast travel point. Wyll is easy to miss, but he's training the tiefling kids inside the druid grove. And Lae'zel got herself trapped by tieflings, south of the grove, should be on the way to the goblin camp.