What fluid goes in the storage container on left side of motor that has a full and empty mark power stering sits just below this one cap says do not open when hot?

The storage container on the left side of the motor that has a full and empty mark and the cap that says "do not open when hot" is the coolant expansion tank. It holds excess coolant that expands as the engine heats up. When the engine cools down, the coolant contracts and is drawn back into the radiator.

It is important to keep the coolant level between the full and empty marks on the expansion tank. If the coolant level is too low, the engine may overheat. If the coolant level is too high, the expansion tank may overflow and cause the engine to lose coolant.

Do not open the coolant expansion tank when the engine is hot. The coolant is under pressure and can spray out and cause burns. Wait until the engine has cooled down before opening the coolant expansion tank.