I am very new to this and am looking for some insight. Lately I have been trying to evoke Beleth and something happened that I’m not sure how to process. I was meditating on Beleth’s sigil and calling his name when suddenly in my mind appeared in front of me a cabin in the middle of a body of water. A long wooden pathway extended from the door to where I was standing. Upon reaching the door the surrounding atmosphere was bathed in a purple glow and when I entered the cabin all I could see was a strong purple aura. I then started communicating and made my request but am unsure as to whether or not I was actually conversing with Beleth or just talking to myself. Like I said I am very new to this so I am uncertain if I am doing things correctly and am looking for any opinions and advice. Thank you.
My advice is to try the same pathworking, but this time focus on the purple aura in the cabin and ask it to take a form that can communicate. Once it does so then ask your questions to it 
But the fact that it was purple seems to suggest your picking up something to with the realm of the 3rd eye. So it maybe him but your not picking it up in form that can communicate yet.
Sounds good, you weren’t expecting it and the symbols all seem to represent good things, you began by following a given path to a gateway (water is a gateway, think of the Lady Of The Lake’s arm rising from the water with Excalibur in for example) and then entering an astral (or at least, non-physical) space, through a second portal, to a location where an energy resided, so I’d take it as a positive sign you made contact. Btw please check your messages (top right of the screen by your avatar), thanks! 
Entered the cabin again. This time I listened to the album Dark Side of the Moon while meditating. I didn’t see anything noteworthy in my mind but when I asked questions the answers I received were immediate and required no thinking on my part so I believe I made contact. I spoke with Beleth for the entirety of the album and felt that the music acted as a catalyst for him to speak through. I suppose the next step is to evoke him for a physical manifestation?
Yes I think the third eye is involved as just about every time I meditate the area of my forehead between my eyebrows pulsates/vibrates almost to a painful level
I’ve got a feeling it will help to give him a physical base here - a crystal maybe, or a sigil or something, that was my immediate instinct on reading this, to strengthen that bridge you’ve been given. Hope that’s a constrictive suggestion, ignore if it feels wrong!
How exactly would I go about attracting him to a physical base, and should it be something that I keep on my person?
You could or simply place the sigil in your sacred space/altar. I even draw sigils on myself if i want the connection to be a direct link to myself.
Thanks for the reply. I actually have a sigil that I carry in my wallet that I forgot about, i guess that is essentially the same thing? Also, this may be a bad question, but in your experience about how long does it take goetic spirits to complete their task/show progress?
Not my forte! As i don’t really work with demon’s in the Goetic style, but i think it depends on how succesful the ritual is and the effort and energy you put into it. Some results will happen almost immeadiately others will take longer to manifest because you have to create situations for it to manifest. if you get what i mean?
Yeah that makes sense. It hasn’t even been 2 weeks yet so there’s still time for something to happen
Also try and think, what can i do to help this along? Depending on what you asked, what can you do situation wise to help it manifest. For example lets say you want someone you know to pay attention to you and become a friend. What could you do? E.g you could introduce yourself, you could start talking with them. Things to get the ball rolling 
One of the hardest parts of magick for me to learn was the mindset that once I’ve done the ritual, my goal is already accomplished, and to let go.
Don’t wonder if it’s done. Don’t think stuff like “Man, I hope it gets here soon, I really need it.” Don’t even think about it.
Just let go, KNOWING you’ve already achieved it.
Once you’ve done your ritual, your job is just to live your life, taking all the mundane actions you feel the need to take to accomplish your goal.
What you’ll often find is things start lining up perfectly to help you accomplish your goals.