I have an old unlocked, retired-from-use Moto G which I would like to restore to use a supplemental smartphone for occasional texting, emailing, and web surfing for CraigsList sales and the like. I'd like to run it exclusively from wifi. I don't want to use same email address or phone number as my primary smartphone. No phone number is currently assigned to the phone. How can I do this with the least expense/bother?