$500 via Verizon e-gift card (sent w/in 8 wks). Activation of 4G LTE/5G phone on 5G Get More plan req’d. Device must remain active for 45 days. $500 charge back if service cancelled w/in 12 mos or eligibility req’s are no longer met. See vzw.com/bring-your-own-device for details.
You can use any WiFi network you have the credentials to be on. If it is a secured WiFi network (which any well-to-do network should be) then you'll need a username/password. If it's an open network then any body can connect to it willy nilly.