This is by far the most advanced and time consuming part of any virtual project. I will attempt to describe every step in detail, yet hopefully in a simple and easy-to-follow way.

Main applications

Reaper (Win/Mac, free to $60)
Davinci Resolve (Win/Mac, free)
Final Cut Pro (Mac, $299.99)

Additional applications (optional)

Flat IO (Win/Mac, free to $60/year)
MuseScore (Win/Mac, free)
Vordio (Mac/Win, cca $105)

Affinity Photo (Win/Mac, $49.99)

Melodyne (Win/Mac, free trial, licence 99€-699€)