A character (person from the 21st century) is going to be sent back to Europe in the late 16th century.
The plan is to upon arrival, immediately attempt to contact someone who is both reasonably intelligent, held in high standing in society, and reputed to have a generous, patient disposition. Then, the time traveler will have to prove to them that they are from the future.
What proof can they give that would have a good chance of convincing this person from the 16th century that they are indeed from the future and not just trying to trick them or totally insane?
Reasons for the characteristics of the person the time traveler will meet
The reason why they have to be held in high standing by society, i.e. a respected philosopher, professor, or clergyman, and given that the destination is the 16th century, they may be all three, is that they can then be a respected ally to the traveler, explaining your situation to others who trust him.I imagine they couldn't be the pope or a king as they would likely be far too busy to hear the time traveler's case in the first place.
The reason why they have to be intelligent is that, since people back then had no concept of being able to travel through time, an uneducated peasant probably would not even begin to fathom what you sere trying to explain, or if he or she could come to comprehend the idea of time travel, they may very well be unmoved by any proofs that you are a time traveler as the notion would be so absurd. Even educated people may perhaps dismiss this notion as ridiculous though.
Finally, they absolutely must be of a kind temperment because an impatient or harsh man would probably just tell you to get away from him and quit babbling nonsense at best. I imagine the time traveler would first flatter our selected person, and maybe even present them with gifts.