The recommended 1st oil change is at 3000 miles. This is not in the manual but from SOA telling dealers. I couldn't tell you how much of that is based on financial, safety, or scientific reasoning.
Currently running dealer oil, so I'll have another Subaru UOA, (Have free dealer oil for pretty much 150k miles.), but I'll probably switch over to Pennzoil Ultra 5w-30 @ the 6k mark