Dion Fortune's "The Mystical Qabbalah"
Agrippa's books of occult philosophyhttps://en.wikipedia.org/wiki/Three_Books_of_Occult_Philosophy
Look for explanations (golden dawn or thelema?) on the Lesser Ritual of the Pentagram
Can't think of anything entry-level, I like Jodorowsky's The Way of Tarot, but it's a big brick
Check all of that first, then move on to something more advanced