Stories should all (for me) start like Breaking Bad.
You can apply that to any kind of story, doesn´t matter the genre.
I don´t need to understand why his pants are flying around and why
he is in his underwear or why there is some liquid coming out of the
camper at this point of the story. Nothing needs to
be explained, I don´t care. I want to get hooked to what´s going on,
I want to be left with the feeling of wanting to know more.
The Star Wars episode IV beginning, that BoomerZ mentioned, is similiar for me,
I don´t need to know who Darth Vader is, I don´t need to know anything about the
universe or the space ships and that´s exactly what gets me hooked, I want to find
out who he is during the story.
The big mistake of many writers is that they think that the reader finds all the background
information interesting, how the magic system works and all the details that "you need
to understand" to understand the story. It all makes me stop reading the story. I want
short and super interesting clues and not all of your thoughts, infos and explainations