Thanks for reaching out Nievska,
It sounds like you have some concerns about using the same Apple ID for multiple devices. We can help.
While we recommend one Apple ID per person, you can definitely use the same Apple ID on more than one device that you use. This will allow you to keep your information shared between all your devices, allow for Handoff and Continuity features to work, and allow you to share your personal data and photos through iCloud.
You mentioned that one iPhone no longer turns on. This sounds like a hardware issue, and wouldn't be related to the Apple ID used on the device. If you are unable to charge or power on your device, you may need to look into hardware service for it.
You can connect with Apple directly using either Get Support or if you're in a region without direct support options, you can also Contact Apple for support and service.
Hope that helps.
Take care.