We add as many controller configurations as possible to the frontend so that you can navigate through them, but for many of them you need to reconfigure them to work in the emulators.
To do this, you need to open the frontend menu with the START button and go to CONTROLLER SETTINGS > CONFIGURE A CONTROLLER.
PS button.If this does not work, try enabling overscan in the menu system settings selection box. You can find more information in this tutorial.
If you have a black screen on the PC monitor (HDMI or DVI) edit the recalbox-user-config.txt file (update at startup) and put a # in front of the hdmi_drive = 2 line (if there is not one already). You can find more information in this tutorial.
F4, then press ALT + F2. You can get a lot more information from this tutorial.