Andriod- Blank screen in app

Hello! I wanted to try building an Android game. So first, I made a test and I did everything to set it up. I was excited when started building but, when it was done the screen was black and nothing happened and if you wait a minute it says the application is not responding. So does anyone know what's the problem? Help will greatly be appreciated! :)

I’ve been using an old Android that couldn’t run unity apps, but the ones now work perfect with unity. ( I would of posted this a long time ago)