Android app will install but not run

I'm trying to build a basic 2D game for Android. I cannot seem to make it detect my device from a USB cable and I know it's not the cable because I can access the files on the device from the file explorer on my PC. What I am doing is downloading the .apk file directly on the device and trying to run it there. The app will install but when I go to open it, it will just give me a black screen. I am using the latest stable version of Unity. Any help would be greatly appreciated!