Finding a drive adapter to re-use the old hard drive from a Macbook Pro early 2015 13"

It is quite possible that there may not be an adaptor. I don't believe Apple used these for very long, so...

I would think returning it and getting one of the OWC drive adapters for that specific drive would do the trick. Like this

eshop.macsales.com/item/OWC/MAU3ENPRPCI

And to destroy an old SSD? Take a hammer to the individual chips on the drive's circuit board, that should do it. Try and recover data from plastic and silicon shards...