I am new but I found the low water point drains (blue and red hoses) almost directly under but toward the edge of my fresh water tank (they are hanging down), the valve by the water pump drains the freshwater tank through the blue hose and then I go under and unscrew the cap on the red hose to drain the water lines etc. My 2018 2501TS includes a pickup tube and valve for the antifreeze to the water pump.
Emm-dee and any other "veteran" please correct anything wrong in what I have stated. Bad info is much worse than no info.
Again, I am brand new and the above is based on my hands on finding the hoses and valves with much help from this site. The winterize thread has pictures of the low point drain hoses.