Hi there!
This is expected behavior for the board. Since there is no mouse, keyboard, or touchscreen connected, the board is receiving no input, so it goes to sleep (and shuts off the display). Because there is no battery detected, Android displays the "Connect your charger" message.
To solve your display issue, please connect a USB mouse and/or keyboard to the board (you should be able to plug them in after the board is powered up and have them operate correctly, however I recommend plugging them in before powering the board up if possible). Almost any USB mouse and keyboard should be compatible. Once the board is powered up, you can use the mouse just like you would with a computer. You can shake it to wake up the display, and you can click-and-drag the lock icon to unlock the board and get to the Android home screen.
If this doesn't solve your issue, please let me know.
