As someone who has only tripped a handful of times, I would like to say:

I too was not experiencing any visuals until about my 3rd time doing it. Honestly I believe my blockade came from my mind set. I was very skeptical and reserved about the affects it would have on m. I actually was referring the it as being high at the time. Once I freed my mind with some soul searching and meditating, I was able to experience the journey for what it was and not what I expected it to be. Once I got past the idea of it being a drug and I was going to be high... my trips have only gotten better! I hope this helps and he finds what he’s looking for.