It‘s an Arduino Uno, but the specific model probably isn‘t what you were asking for 
As for where to start, you should probably start with Processing! Just create the Code and see if it works with mouse/keyboard Input. Once it does you can think about exporting the input to a Controller or somesuch.
Anyway, i‘ve got little experience with using Controllers other than arduino with Processing, so don‘t put too much weight on my words, but i‘d say using Arduino is probably a lot simpler than using a controller of some other kind.
Apart from drivers/libraries and other things you might need, there‘s always the risk that some might not have been updated for years and don‘t work anymore.
You probably won’t have that Risk with arduino, since everything you‘d need for this project is the arduino serial library. It‘s pretty easy to use and relatively up-to-Date.