A prion is an abnormally folded protein. It would either have to enter because your skin cells let it in (not gonna happen), it survived your nasal cavities, your saliva, your stomach acid, and your immune system. Any of which will denature a protein. Once a protein has lost its folds it is useless and can't spontaneously get them back.

Proteins are chains of amino acids, but their entire functions relies on how they fold. That is why drugs can only imitate them, but can never be them. Cocaine is an imitation of dopamine, but since it's not actual human dopamine it often gets stuck on the dopamine receptor and doesn't come off. This is what causes the damage from cocaine use. (like a key that opens the door but gets permanently wedged in the lock). Real human dopamine wouldn't do that.

You are not going to get prions from another human unless you eat that person. I.e. cannibalism. If they have kuru in their brain and you eat their brains you could be at risk to get kuru from the massive intake of their contaminated brain tissue.

There is zero chance you'll get it from their sweat, urine, fece, saliva, ect. Those all denature proteins. But if you eat that person, especially their brains, then yes, you are at risk to get a prion disease like kuru.

So don't eat people.