iPhone 5 display won't work after opening

I was planning on replacing my iphone 5 glass screen so I took out the 2 small screws and got the screen part to come out of the rest of the phone. I was trying to take out the screws of the plate covering the ribbon cables but didn't find a screw that was the right size. I gave up and closed my phone back up. now my iphone screen is completely black, but it still makes sounds/vibrates when I switch the mute button.

Im really worried because my screen is completely black.

Power button isn't working either ( doesn't make on/off sounds). is there a problem with the ribbon cable? how can I fix this? I barely did anything :/

An hour after posting this it was dark, and I realized that the power button can make the display turn from black to a gray/blue blank screen. So power button still functions. I dont think home button works