Look for a brown or gray square box, about a foot square, hanging on a wall. May have vents. Could be under the oven or refer. Start looking at walls close to where the power cord is located on the outside of the trailer.
If your plugs aren't working, one of them generally in the bathroom, is a GFI, with a test and reset button. Make sure you check it and it is reset.
Also when you find it, the breakers control all of the 110 volt AC poser. The fuses control all the 12 volt DC power. Might want to sate your actual problem, and maybe we can help point you in the right direction.
2012 Ford F250 ext. Cab 4x4
2002 Jeep Wrangler Sahara
2008 Yamaha V-Star 650 Classic
2008 Work and Play 18LT