Look up the exact model of the phone then check GSMArena or a similar site to see which bands it supports - then check to see which bands your carrier requires.
Also, in the US I usually recommend eBay or swappa for phones - their buyer protections are robust and it's almost trivial to return the phone if there's an issue that isn't disclosed in the sale listing. Buying used/refurbed things on Amazon is a crapshoot in my experience.