It's hard to give you a specific location of the AC drain exit since we don't know the year and model of your trailer, but almost all Airstreams with factory air will have a AC drain that exits the trailer in one of the wheel wells. This drain can get plugged with debris and/or mold over time. Locate the drain exit in the wheel well and use an air compressor t blow it clear. If that fails, try snaking a small wire up the tube. It's possible that the blockage is at the entrance to the drain tube which would require that you go up on the roof of your trailer and try to unblock it from there. That may require removing the AC shroud to gain access to the drain.
You mentioned that you get water on the floor near the kitchen, if the above action does not solve your problem, that could also mean that the drain line down to the wheel well has broken or become detached from the connection in or near the wheel well. If you can get access to the area on top of the wheel well by removing some of the drawers do that and see if you can find the drain line to repair.