Audacity

Audacity

Audacity is an audio editor and recorder available for Windows, macOS and Linux operating systems.

The fundaments of cutting

Link to tutorial
Keyboard shortcuts Edit ------- > copy, cut, paste, duplicate, split cut, delete, split delete
Edit ------ > Clip boundaries --> split, split new

Volume and envelope tool

more here
ducking and auto-ducking

Basic effects

Fade in/out
Amplify
Change tempo, change speed, change pitch
Paulstretch
Reverb
Noise reduction ---> reduce and residue
Generating silence or tone