Your development team has reached the maximum number of registered iPhone devices.
I am use the free provisioning file. So how can I delete old device and use my new iPhone to develop my app. only way is use a paid account? or register a new Apple ID?
Free provisioning, aka a Personal Team, has some pretty significant limitations. For the details, see Developer > Support > Choosing a Membership. That explains how App IDs, device registrations, and provisioning profiles expire, currently after a week. So, the easiest way around this limit is to simply wait.
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Quinn “The Eskimo!” @ Developer Technical Support @ Apple
let myEmail = "eskimo" + "1" + "@" + "apple.com"