ok, go to a honda dealer and buy coolant from them or any auto parts store. they sell premixed coolant/water so use that. don't just put water, but if you must use distilled water. if you buy premixed coolant/water at auto parts stores make sure whatever you buy it is safe for aluminum engines(if you don't it can cause a lot of problems).

now, that white bottle you refer to is the overflow tank. it is used to store coolant when the car warms up. when the car warms up, the coolant expands and it needs a place to go so it goes there. to properly check your coolant in your cars cooling system, the car must be cold(let it sit overnight). the reason why is you really want to check the coolant level in the radiator and if you open the radiator cap when its hot, coolant will go everywhere and it will burn you. so make sure the car is cold and open the radiator cap and see if there is coolant in the radiator. it should be up the bottom of the neck(part of the radiator you took the radiator cap off of) of the radiator. if its not, fill the radiator up. then you need to fill the overflow tank up. refer to your owners manual for more info, but on the the tank there should be marks indicating the max level and min level. it should be up by the max but can be anywhere between the two levels.