The valves you are looking for are under the bed, or in the bottom of the cabinet that is under the rear windows.
If you remove the mattress you will find an access cover . Pull it and the pump and valves will be under it. I say valves because you should have a tank drain, a cold water system drain and a hot water system drain. The will be grey handles that are connected to pipes that run into the floor.
The other way to find the valves is from underneath. The outlets just stick out of the floor. Find the pipes and you know where to look inside.