Explaining what each is specifically good for
Pick up a copy of the Goetia, which you can find for free online with a simple Google search. It tells you what the offices are of the 72 demons.
Black witch coven
They have a section that lists names and what they’re helpful with
Goetia, Black Witch Coven, and Satan and Sons
Google “72 Goetia” and you’ll get tons of websites.