Give me a scenario of if someone from the 1800s came to the present?

Like we would have to explain iPhones, computers, cars, the internet, but give me a story.

Ex. Thomas came from the past and I met him and showed him around…

Cars look like ufos to them

The 1800's covers such a huge range that to get any kind of consistency you need to pin this down. The beginning had the US confined to the east coast and still dealing with the revolutionary war. Diseases we haven't heard about in decades were common - some of which he might give you (like tuberculosis) and if he was picked out of a random location he might have been a slave or indentured servant with several years ahead of him. It would be very likely, especially early, that he could not read or write.
He would, for much of the century have seen bottled foods but not canned. The availability of fresh foods all year round and refrigeration without blocks of expensive ice would have astounded him. Once he understood our prices, they would have dismayed him (they dismay me.)

This isn't really a story but what I'd do is tell them that I possessed a device in my pocket than can contact people all over the world and retrieve every piece of information known to mankind and then just watch them freak out

Thomas did not understand traffic safety and quickly died.