spirits live in the mind network. at the start of a spirits life it can feed on any kind of emotional energy, as it grows it develops a taste for certain kinds of emotions.
we are all surrounded by spirits, we unconsciously culture them throughout our life, and they culture us.
youve got to create a symbiosis with them otherwise they become parasitic. think about what they want, what emotions they have learned to sap from you, and how you can use that to your own ends. thats how people make familiars and tulpas. they have little direct power over the physical world (unless you know how to enrich them, which is advanced complex shit) but they can affect it in an indirect way, through people and through randomness which have a surprisingly powerful effect on the world