So, OSC requires the desk to be networked with some device (& software) that can send OSC commands. The available commands are detailed in the manual at https://www.zero88.com/manuals/zeros/setup/triggers/osc. These let the external device/software trigger certain actions on the desk, for example playing a cue on a playback. The desk cannot send OSC and therfore cannot provide feedback to the sending device.
Networking the desk and the sending device need not be complex. Connecting both to a normal domestic router would be sufficient but note that the router must NOT be connected to the Internet. Some routers can get a bit funny without an Internet connection
What you use to send the OSC commands is up to you but a popular piece of software is TouchOSC by Hexler. There are two versions of this. The original version (Mk1) allows you to define a control surface with (among other things) buttons, sliders and rotary controls. This version is free but is not as flexible as the new version.
The new version can be used like the original one but has more features including a scripting language with which you can achieve quite complex results but, for access to this you will need to get a licence. There is a very reasonable, one off, fee for the licence.
I don't think OSC can receive inputs from game controllers but check this out for yourself on the Hexler website.
TouchOSC can be run on Windows, Android, Linux, iOS and macOS. More information can be obtained from the Hexler website https://hexler.net/touchosc
Other software is available, all you need is to be able to send OSC commands as defined in the ZeroOS manual but I have no first hand knowledge of what is available and its suitability.
Hope this is helpful in getting you started.