Well, the usual troubleshooting steps are
start with the RetroPie image from retropie.org.uk/download. It's a tested and mostly stock Raspbian image and the best baseline system to start experimenting. make sure you have an adequate power supply and you don't get any under-voltage warnings. test if the device is detected by the OS by running a few command line utilities # see what USB devices are connected with lsusb # see what input devices are detected by the OS and what kind (gamepad/keyboard/mouse/etc.) cat /proc/bus/input/devices test if the device inputs are registered in the system by running a few joystick/gamepad testing programs fromt the command line that capture the button/joypad/d-pad presses and show them on the terminal: # 1st joystick jstest /dev/input/js0 # 2nd joystick jstest /dev/input/js1 # another testing utility evtest