I always thought MCU's Thor was a fictional expansion to the actual norse God of Thunder. There are some quotes in the first Thor movie that supports this:
In ages past, they looked to us as gods, for indeed so many times we saved them from calamity. We tried to show them how their world was but one of the Nine Realms of the Cosmos, linked to all others by the branches of Yggdrasil, the Worlds Tree. Nine Realms in a universe of wonder, beauty, and terror that they barely comprehended. But for all their thirst for knowledge, they let our lessons fall into myth and dreams.
When Thor wants to go to Jötunheim after the ice giants try to steal the tesseract, Fandral says:
This isn't like a journey to Earth, where you summon a little lightning and thunder and the mortals worship you as a god. This is Jotunheim.
And in Earth, when Jane and Darcy are starting to think that he is actually the Thunder God, Darcy says:
A primitive culture like the Vikings might have worshipped them as deities.
But in Infinity War Thor says he is 1500 years old. That means he was born in the year 500 after Christ.
So, is this possible? when did the norse people start worshiping Thor?
Note: I took the quotes from the original Thor movie script here