Oh oh, I have had this problem and I have favorites!
So for music, MusicBee, it has a great tagging system and music organization for free. I just run it in the same library and have a folder for unorganized files I add new stuff to.
For movies and TV shows, I know there is free options but I hate them. I dont know, I am a dumb dumb I guess but I can't get most to work for me. Filebot, so good, I will parade for filebot it is so good. I know it is paid but I paid for it twice. It can even keep the file linked so you can keep a torrent running and will do so much so simply. It kind of works for music but not really but movies and TV its like a wizard.
Books.... I do them by hand. Man thats still a thorn but its clean.