Welcome,
Nice DMT you have there
No need for a shaman in my opinion, let your intuition and the molecules themselves be your guide. I have administration tips
here, but I strongly believe that these things are best learned and explored on ones own so-to-speak, which can include others of course.
The word shaman fits in certain cultural contexts, but I think there are better words to use nowadays for a person seeking to explore hyperspatial possibilities with exogenous use of endogenous neurotransmitters. Labels aren't exactly necessary here because in my opinion what we are doing goes so far beyond our language anyway.
Explore the link as well as the rest of the site, you will get a feel of others techniques and eventually you will have your own personal crafted method of psychedelic use that you will find works best for you.