Greetings & Welcome!
Your van looks pretty complete as is. Start with the drive train. Everything connected to how it runs, drives, and handles, including the tires. Then check for any leaks, and if it has any, get them fixed promptly. (Roof, doors, windows, etc.)
Next learn how to use all of the existing appliances safely, with emphasis on safely. If the cushions are bad, repair or replace them. A new table mount should be available at any RV supply, but keep basically everything intact to begin with. If the carpet can’t be cleaned, put a throw rug on top of it.
Then USE it. Using it is the best way to discover if it’s fine as is, or if you want improvements. Too many people make those improvements first, then regret it later. Changes cost time and money that could actually make it worth less. Good quality originals are in demand, remodeled ones aren’t.
Restoring it may or may not be worth it. Sometimes lowering your expectations can make you happier in the bigger picture. My philosophy is to never invest more into a vehicle than you can get out of it. I lost a bundle when I violated that rule, and it was the worst camper I’ve ever owned.
That’s a great vintage of a van, and repairs are cheap and easy. They’re much more reliable than newer ones, and if you lucked out and got a 302 engine, it may even get excellent gas mileage. Simple and practical also has a lot of advantages.