My screen is blacked out and not working

Hi, and welcome to the Apple Community.

You might want to browse through this adiscussion thread on a similar topic

https://discussions.apple.com/thread/7512605

If you want to take your iPhone to a nearby Apple Store: 

a Genius Bar reservation is recommended:

How to make a Genius Bar reservation at your favourite Apple Store, and get help from an Apple expert.

(Change the country at the top to suit, if needed)

Genius Bar Reservation and Apple Support Options - Apple

https://www.apple.com/retail/geniusbar/

or

Product Service and Repair Information:

https://support.apple.com/repair-products

All the best :-)