Davinci Resolve ✅ [free version is good for most amateurs] Originally, it's a color grading software. But the current version is a kind of all-in-one video post-production software. It can do editing, VFX, and color grading for video. Also, since it purchased the Fairlight, which is a DAW, and integrate it into Resolve, it can also handle the post-production of soundtracks.
Existential.Audio/Blackhole [free] [Github] ✅ BlackHole is an open-source virtual audio driver that allows applications to pass audio to other applications.
Loopback ✅ It allows you to create many virtual audio devices and route audio from apps and other audio devices to any channel in your virtual audio device.