Welcome to the forums and to the project phase of vintage Airstreaming. We have found the folks here very experienced and willing to share information. As you read through the threads you'll start to know what questions to ask.
Many here will recommend to start by making the trailer safe first, then make it campable, then make it your own.
Safe means make sure the running gear (frame, axles, bearings, brakes, safety chain, hitch coupling, exterior lights, emergency brake switch and power, etc. work as intended).
Campable means the interior systems you want and need work correctly (propane appliances - no propane or exhaust leaks, plumbing no leaks, fresh and waste tanks hold liquids, water pump works, electrical 120 v and 12 v work, layout for sleeping camping etc. works for you).
Make it your own is about the colors and decor and fabrics and flooring and the personal touches you want.
At first you'll be in a "discovery phase" while you figure out where you are starting. With luck, your new trailer is already safe and campable, but you'll want to verify that through inspection.
This part is fun, too, so enjoy.
Here's a link to our latest project thread, if you're interested; https://www.airforums.com/forums/f39...er-155180.html
Keep us posted on your progress,
Roy and Marie