I got my certification at Kripalu. They used to have a live/work arrangement. Many ashrams have ways to be immersed.

As for shamanism, you don’t have to become one to study their systems and modalities. And if the lineage has appointed someone or given them permission, cultural appropriation doesn’t come into it. I’ve taken some classes from Ray Crist, an Anglo who apprenticed in the Q’ero lineage for 12 years and was initiated by his teachers Don Sebastian Pauccar Flores as a Kuraq Akulleq. This Quechua title translates to “seer” or “visionary” and comes with it a directive to share the Q’ero teachings to other nations as a planetary representative of the tribe’s culture and medicine. I recommend Ray, but there are other folks out there, doing this with permission.

As for the psychedelics, ideally, they take work and preparation. And having a guide or mentor. If you haven’t read it, you might like the book The Cosmic Serpent, DNA and the Origins of Knowledge. The link is to my review of it.