I love peru..
Oooh recommendations:
Learn basic Spanish, and download Google Translate on your phone.
Hot and Humid in the Amazon... you will probably need some sort of bug spray (there are lots of organic ones). Also long pants to wear, bring a headlamp if you have any night excursions.
Plus long sleeves and pants in the jungle is always a good idea, lots of bugs. I would drink lots of greens prior to going bugs dont like the flavor of the blood when you drink spirulina/ other green powders.
Its going to be so fun, I love the jungle the amazon is hands down my favorite place to go, the nature is incredible and pachamama is so present there!!
I would see if you can also do Kambo, in combination with Ayahuasca. However Kambo is not a ceremony, it is medicine but also helps cleanse the body.
Drink lots of water and have so much fun!!!! The peruvians are some of the nicest people. Oooh and eat lots of tropical amazonian fruits!