There are some great family attractions on the coast. Obviously the beach is the number one attraction, but many communities also offer the opportunity to catch live crab off the docks which is always a hit with kids. You may want to consider some of the following:
Seaside: Indoor carousel, kiddie rides and Seaside Aquarium.
Newport: Oregon Coast Aquarium
North of Florence: Sea Lion Caves
South of Bandon: West Coast Game Park Safari (petting zoo with opportunity to pet exotic baby animals).
Reedsport: Umpqua Discovery Center (Interactive walk through natural history exhibits). Nearby is a dependable location for elk watching.
Between Gold Beach and Port Orford: Prehistoric Gardens (rainforest walk with 23 life size dinosaur replicas).
You didn’t mention which part of the coast you are visiting, so this list includes attractions covering almost 300 miles of the Oregon Coast. If you’d like to let me know where you will be spending your two days, I can get more specific about that region. Hope this helps for now. Happy exploring!