Serial number is unique to the laptop and different from the Model number (A1466) Use a Wall power adapter to turn it on to check the specs. Apple menu - About this Mac. www.macbookadapter.com

I got a battery for mine from Amazon. Worked totally fine. https://www.amazon.com/gp/product/B07SDBKDDK/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1

Check out MacSales.com for upgrades and Everymac.com for other information.