Welcome to the club! The good news is that the manual for the trailer itself is absolutely useless, so you won’t miss it. The better news is that there are online manuals for each of the subsystems on board, such as the refrigerator and the water heater and so forth.
Just figure out which model of (let’s say) refrigerator you have, go to the manufacturer’s website, and download the manual. Even if that particular manual is unavailable, it’s often the case that the more recent manuals are still valid, in large part.
And if you have questions, just post them right here – – us old-timers love to answer them, instead of doing the things that we are supposed to be doing (like household chores or work).
2012 Fun Finder X-139 "Boondock Style" (axle-flipped and extra insulation)
2013 Toyota Tacoma Off-Road (semi-beefy tires and components)