Hope your search for manuals is successful. Even if it is, do understand that your trailer might have had 4 or 5 owners - some of whom may have been "inventive". If you're lucky you won't find too much garden hose used as plumbing.
Now - the forums are a wealth of information, but the SEARCH function is well - sometimes awkward - and sometimes impossible. Brings you the whole haystack and dares you to find the needle.
The most newbie proof search is to click the SEARCH tab, and go down to the entry line under "Google Search" - try a string of keywords to narrow searches that bring up 20,000 responses. For instance "plumbing" will give you way too much "plumbing rear bath 76 sovereign" will be much narrower and probably give you 2 or 3 threads.
Most of all keep posting - then one day you'll have the "golden post" (It's the one post between being an untried rookie and a grizzled veteran.)
Today is a gift, that's why they call it the present.