Actually it should be helpful, and not everyone is aware that it exists. Which is why I linked it.
Also because the issues you have mentioned so far point to things that should be addressed by reading through the wiki, following the Quick Start setup and then for particular issues search to see if they’ve been addressed.
In v4, there should be a Save button right at the top of every settings page.
And Completed Download Handling should be enabled in order to move your downloaded files to your Root folder (which as noted should be enabled by Default) https://wiki.servarr.com/en/sonarr/system#enable-completed-download-handling So if they are not moving then it’s possible you don’t have Categories setup in your download client. You’ll want to check that. You will also need to manually import anything that has already downloaded in order to move them from Completed.
So again; please read through the wiki, follow the guide, maybe try and find a Mac focused video you can follow. And if after that you are still having issues, come back and provide details of where you’re stuck and what you have already tried yourself to fix your own issue. Screenshots of your settings etc. can help. Depending on the issue/error logs may be required.