How to install the latest Linux Kernel, Mesa, Intel/AMD GPU drivers, and Xorg.. on Ubuntu 18.04 LTS?

On Ubuntu 18.04 LTS, how to get:

• Linux Kernel: 5.0 or newer.


• Mesa Library: 19.0 or newer.


• Intel Graphics Driver: ...? (latest)


• AMD Graphics Driver: ...? (latest)


• Xorg: ...? (latest)

I have two machines, one with a GPU from Intel, the other from AMD.

Another way to ask this question would be: how to optimize gaming (e.g. Steam) and make the most out of newish-hardware, specifically on Ubuntu 18.04 LTS?