Where to start…

[RVgal]

We purchased a used Airstream 19 and I’m feeling a bit overwhelmed trying to figure out the power, water, etc systems. Any chance someone is in the Fairfield CT or Westchester NY area who might be willing to give us an overview or beginners tutorial? I’m working through the manuals but just afraid I’m going to screw something up. Thanks

[Acheron2010]

If it was me....I'd hitch up the trailer, and make an appointment with Colonial Airstream in New Jersey. Spend a few hours with those folks getting a proper briefing on your trailer.
Alternatively, there is the Charter Oak Connecticut Airstream Club, and several others in the New England area. Reach out to them, and they will definitely help you with your new purchase. Oh, and join their club.
This video from Patrick might help get you started.