what does it say in the manual? 2009/10 models say to change after for the first time after 200k or 10 years. Newer models I think says 100k or 5 years, not sure.
If you want to add more, just buy a bottle of type 2 coolant from any 3s dealer. It is already pre-mixed, do not add water. Fill it to the max on the bottle when engine is cold.
Dealerships or honda pit stop usually just top off the coolant bottle with water.