This is a big book, filled with extended philosophical dialogues that are essential to the adventure aspects of its plot, and there are a number of mysteries that give the whole thing its zing. If you know any more than that going in, you’ll miss out. Much of the fun is in not knowing where things are going, and immersing yourself in the habits of mind of the characters.
The book comes with a timeline at the start. Don’t read it. There’s a glossary at the end. Don’t refer to it. There are plenty of reviews online. Don’t read them. If you like Stephensonian fiction, buy it and try to puzzle things out along with the characters: by using your capacities for imagination and reason.