2001 terry travel trailer model 37???

I am extremely new to the travel trailer seen but was hoping for some input. I have a friend who inherited A terry trailer model 37(would that be 37 feet?)It has been on a site since new.They used it for the year and decided they barely use it and don't want to pay the $2500 site fee and also have no place to park it to use for trips.My questions are 1:is it a 37 ft, 2: can I tow with a 99 f250 diesel truck(gvw show 11500 and truck supposedly can tow 13100)and 3:it has a sliding glass door on the side:can that be towed(most I would do is maybe 50 miles)without flex/ cracking and 4: where can I find tips and other hitch items I would need if I were able to do this project. oh, I didn't mention, the trailer is very clean, two slide outs and FREE!!!!thank s in advance for the help