Spirits come from the Earthen, Spiritual, and Astral Realms. They are a transitional form of mortal entities who have lived and died in any of the Realms.
There are trillions, countless numbers, of spirits and living entities within the 3 Realms. Considering all of the forms of life that have existed and lived over the billions of years the Universe and Realms have existed, you cannot even fathom a number of life forms that have come and gone, and those who continue to live.
You could live a millions lifetimes and never be able to interact with every single form of life that has ever existed. The finite number of lives would be to each species/race, but overall it’s a magnificent number across the whole of time itself. You couldn’t even fathom a number that would define how many different species/races have lived.
In the bigger picture, some species/races would be more rare comparatively to others, but again, that is quite a large conversation. You would never have enough time in this lifetime to communicate and interact with 8 billion human spirits or entities, and you’re just defining humans alive on Earth right now. That’s just the population as of today of humans alone – the estimate is around 110 billion since the beginning of humans as a species. That’s just humans, so you couldn’t possibly conjure and interact with all spirits of all species/races in your lifetime.
We live on a planet that is microscopic in the face of the size of the Universe, and in light of that fact, our planet has hosted an incredible volume of life in its 4 billion years. It has cycled through an innumerable variance of species/races over time, and in most cases, millions have existed over the whole of time of each species/race. So, is there a finite number of any species/race? Yes. Would you ever have the chance to actually reach that number of interacting with each species/race in your lifetime? Absolutely not. Not even if you started the moment you were born and did nothing else but that every day, every minute, every second, until you died. You wouldn’t even scratch the surface.
How long each species/race lives is a massive variable. There could not possibly be one answer, because there are billions of races/species of life existing across the whole of time and the 3 Realms.