I found that the best way to test used solar panels is to connect the two panels leads together (yes, dead short) and then apply a clamp meter that reads dc amps. Here is an example of a dc clamp meter...
Here are some a good article on the disadvantages of leasing:
https://www.consumerreports.org/energy-saving/real-cost-of-leasing-vs-buying-solar-panels/
https://www.chooseenergy.com/news/article/pros-cons-solar-lease/#:~:text=Solar%20leasing%20does%20have%20some,the%20works%20to%20replace%20it).
I frequently get those messages. It just means the package is at the post office. Typically the post office will have it delivered to my home within one to two days.