The cooling system of your truck is one of the most important to maintain a healthy engine. Coolant flows through many passages and hoses to keep the engine from overheating and causing damage. The cooling system is fairly simple, pump, reservoir and some valves. We as a driver need to maintain a good coolant level of proper antifreeze and it needs to be checked often. Oil is the blood of your engine, coolant is the sweat glands, the engine will fail if either of these doesn't do its job.
The engineers have made checking the coolant on the Cascadia simple. After opening the hood, from the left side, lookup and forward. There is a white/opaque reservoir mounted to the top of the radiator. You can see the coolant level, probably pink in color, thru the body of the reservoir, it is marked Cold max and Cold min. As long as the level is between these marks you are good. Coolant expands as it gets hot so if you overfill the reservoir it will push out the excess.
If the level is below the Cold min marking you must add coolant before driving the truck. The fill cap is on the top of the reservoir. Do not open while the engine is hot, wait for it to cool before opening. Do not add straight water. See your owner's manual for the proper coolant/antifreeze. Once you are satisfied with the level, close and latch the hood and you’re off.