Does the goetia deliver what it promises? I.E teaches all sciences and or teaches the person all languages? And how exactly would that work by just talking to a spirit? Please someone let me know!
Good question, I’m interested in that too…once I read a book in which the magician explained that the spirit teached him in his dreams.
I remember reading in Questing after Visions that with experience you can achieve a state in which you can communicate with entities without using words. It was something like a pure flow of information.
That said, it is possible to gain lots of information in a short time. 
Not speaking to the Goetia specifically, but to the general idea of kinda “downloading knowledge” …
I’ve had successes on several occasions where, in deep meditation, I found myself with a whole, synthesized body of knowledge surrounding the topic on my mind, that I did not “know” before I entered the meditation.
But to be clear here, I was not attempting to suddenly know Latin ir understand Neurosurgery. Having made my (personal) disclaimer however, I would add that I believe such manifestations of extraordinary knowledge to be possible. Yes, absolutely … 
Z
Yes. From what I’ve seen, it’s not an over night thing but rather by-chance encounter’s with people, places or things that’ll bring you towards your goal.
I’ve seen that too. Honestly, they are awesome.