Enjoy the fog! Drive north on one side of the peninsula and back down the other side seeing what interests you. Views, water, boats, etc. Spend a day driving and relaxing on the beach. Spend a day in Astoria with the trolly and waterfront sights. The Maritime Museum is very interesting, one of the best if not the best fish and chips lunch at the Bowpicker across the street. Yes it's a boat and there is always a line for good food.
Ft Steverns is interesting including the drive along the ocean to the Columbia which is the most dangerous entrance in the world racking up about 270 large ship wrecks. Very very little left of the Peter Iredale but the location is interesing. Drive on the beach. And Lewis and Clark sites.