You'll need to get to it under the trailer. You'll either meet to take down tank pan or belly pan to get to where the trap is under the floor to replace the trap piping. Assuming you mean you broke the drain pipe and not the shower pan.
Not fun to get in there.
Piping will be abs sob you'll need abs pieces and abs cement, or pvc pieces and transition cement.
Consider using a HEPVO under there as it doesn't need to be winterized, it should screw straight to the sink drain tailpiece, you'll have to add a male adapter to the pipe on the other end.