I work on a place with different editors and everyone adjusts the voice and music levels by ear and I have watched many tutorials on YouTube to find a way to automatize the process but I haven't find a good way to do it. So I would like to see if you can help me with that. The videos are similar to this where is just the voice over alonf with images and music: https://www.youtube.com/watch?v=In6gCrGeZfA&t=383s
Do you intend to set a specific amplitude for all your audio files throughout your projects? If so, then you should check out the Audio Normalisation feature in Premiere. If you need to set the amplitude of your music whenever a voice over comes and goes, then please try the Audio Ducking feature. You can learn how to use it here. This should save you some time as well as standardise your workflow. Hope this helps.