Tuning the shock will have little benefit for a second time out, lots of skills to develop and concentrating on changing the cars characteristics won't help at all. Your best bet is to leave them middle to stiff and work on looking ahead, hand placement, and your line. There is no correct or easy answer as to where to set the shocks, even if someone had your identical setup (incl tires etc).
If the surface is rough I would nudge them a bit softer, since the tokicos adjust both compression and rebound. You can also use them to balance the car if you are getting terrible push or oversteer, just soften the end thats not getting enough grip. Just try to set them once after the first run and then after that concentrate on all the rest.