Satellite receivers need a direct coax run between the receiver and dish. So one of the connections should be a straight coax cable connection to the outside with no splitters or any other device in between. If you pull the wall plate from the wall (or look behind it some other way), you should see one of the cable tv connectors with nothing but a coaxial wire attached to it. That should be the run to connect a satellite receiver to a connection on an outside wall of the trailer.
The other connection on the wall plate is likely to go into circuit board. The circuit board usually has two inputs. One goes to the antenna on the roof and the other input goes to a connection on an outside wall of the trailer to connect to a cable TV system. When the green light is on, the connection to the antenna on the roof is active. When the green light is off, the connection to the cable TV input connection is active.
There are typically two outputs on the circuit board. One outlet goes through the wall plate to the main TV. The other output on the circuit board behind the wall plate will usually feed a splitter. The splitter will feed the bedroom tv, possibly a radio (antenna), and any outside TV connections.
There usually is not an installed method to feed a satellite signal from the satellite receiver to any of the other TV locations. Normally you would have to get behind the main TV wall plate and do some re-arrangement of the cables back there. You might just have an extra run of coax already installed to the bedroom though which might be just a straight coax cable connection between the "bedroom satellite in" port and a cable tv port in the bedroom. How many cable tv outlets are in the bedroom, one or two?