purchased a prepaid verizon phone card plus want to use it on my at&t go phone
You might try contacting the customer service number for your AT&T phone.
You can't AT&T and Verizon are two different companies and two very different networks. Phones that operate on AT&Ts network will not function on Verizon's. Seriously... definitely will not work. Go get a refund for the card and buy time on AT&T's network.
Call Verizon and ask how.