Advice needed on winterizing water tank and pump

Terryallen.. The only drain for my fresh water tank sticking out of the enclosed underbelly is the low point drain.. I opened that.. nothing in it.. The dealer did not put any water in the tank at the walkthrough nor did they run the pump. I have never put any water in it so I should be fine. I will go to the pump directly under the bed and check it.. Thanks for the advice!