Many writers enamored of the novels of the 19th century, when the novel really took over as a main literary genre, expect to be able to use some of the same literary techniques today. That direction often spells disaster for anyone wanting to publish. Most readers today, totally acculturated on movies and television, won't sit through (read through) a slow descriptive beginning, such as the childhood of the main character or a lengthy description of place. They' re wanting to be hooked right away into or they will move on to something that does that.
Now that's not to say that if you're the most exquisite poet who ever wrote a novel you can't capivate some readers. But most of us want to know right away who the main character is and what the dilemma is. It doesn't have to be the main dilemma but it needs to lead us in that direction. Who is this person we are going to spend a lot of hours with? What does he want? Why is she troubled?
I recently read a first chapter for a potential client in a lengthy novel on racism in America. She writes well and I am interested in the subject so I was ready to like it. But she spent the first chapter setting up a wealth of context for the story rather than plunging me right in and giving the context later. I would not have bought her book.
When you're reading, watch for beginnings that grab you. See if something along that line will fit for your own story.