Ac question

As new as it is, I would bet you could run one A/C. The new ones use a lot less power and come with "soft starts" from the factory. This is a good item to have in your toolbox to track electric draw on lots of stuff, not just RV related. Check while everything is running and add up the values and compare with your power supply's capacity (pick the weakest link, in your case the 15 Amp adapter). You do need to have them clamped around a single conductor, though, not the whole cord. Building a real short extension cord with individual wires makes that easy.

https://www.amazon.com/Etekcity-Multimeter-MSR-C600-Auto-Ranging-Multimeters/dp/B00NWGZ4XC/ref=sr_1_2_sspa?dchild=1&keywords=amp+probe&qid=1592704516&sr=8-2-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUExUlU1TEVaVjBWQVYxJmVuY3J5cHRlZElkPUEwODk5MzI4MzRKNTNDUDc0RDQwNiZlbmNyeXB0ZWRBZElkPUEwMTI5NDUzV0lYMERDT0NEVUJKJndpZGdldE5hbWU9c3BfYXRmJmFjdGlvbj1jbGlja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ==