Welcome to the Forum!
So, you already tried it with PulseAudio Volume Control, yes? It is a Tool for Audio Input and Output.
The github Thing is unfortunately too high for me. So, I can't help with that.
Install a newer Kernel ... Well, there would be the Ubuntu Mainline Tool. It is a graphical Interface to install other Kernels. For this, you would have to add a PPA (a third-party Source). And then you could install it. The follow Video is an older One, but explains it good I would say. You can take a Look at it and decide if You want try it.
