Ice in freezer and water on floor

I have several inches of ice in the bottom of the freezer and water on the floor continuously now. The water on the floor started in summer when humidity was high and seemed to be from condensation around the ice maker/water dispenser (which is not hooked up). There is always water in the tray under the dispenser. Now there is no humidity and the problem is worse. I’ve read previous posts about checking the drain line, but on this model where do I access that part, from the back or inside the freezer. Also is it possible to turn off the freezer but not the fridge?