Witchcraft is defined in so many different ways, really so it depends on the practitioner. Most are either atheists or polytheists, but Christian witchcraft is actually a thing. Typically there’s no belief that Satan exists. Many pagan Gods and Goddesses have human traits, and many specialize in certain things like the hunt, agriculture, war or the home. Many saints in Catholicism were once Pagan Gods and Goddesses.
Keep in mind that there are many, many different pagan belief systems that believe in magic. Druidry, Heathnry, the Celtic system, etc. Then there’s Wicca which draws much of its beliefs and lore from other sources and belief systems; it was created in the 1900’s but I never remember when for sure. 40’s? 60’s? Anyway, there is no one way to be a witch. Everything is up to the individual practitioner to do what they feel is right and to worship the deities that resonate with them.
Spells are similar to prayers, but witchcraft encourages the practitioner to use the innate power of things combined with their own power and will to manifest what is needed or wanted. It’s not just left to the gods to make it happen.