There have been whole books and classes written on this topic! I am going to highlight a few crucial points that I have learned and point you to a few resources where I have learned a lot about good plotting and conflict. Most of the information in this particular post, I learned by taking an online YA fiction class from my local community college. Today you can find the course at Writing Academy (Link below).
I also want to point out that while I hope I write engaging books that people enjoy, I am far from an expert in this area. I am still learning how to accurately apply the things I have learned and I definitely have more to learn! But despite that, I’m not going to let that fact stop me from writing and neither should you! The only way to get better is to keep writing!
No matter how many cool aspects or concepts you have in your book, readers generally care the most about the journey of other people. Whatever story you are writing, it is going to revolve around your main character. Your main character should have a flaw or weakness of some sort. Something they will overcome and some lesson they will learn by the end of the book.
In your book, your plot is your character’s physical journey and your character’s emotional journey is what we call the story. You need both for a good book. On your character’s physical journey, you are going to put your character into circumstances that is going to push them toward confronting their flaw. That creates conflict, which is part of your character’s emotional journey. For example, lets say that your character is painfully shy, putting them in social situations with increasing social expectations would place this person in increasingly painful situations that would create more and more conflict in that person’s life.
For example, lets say your main character, who is shy, hates speaking in front of people. Giving a presentation in front of a classroom full of kids could be terrifying. And by showing their terror and how miserably they fail this simple task ramps up the conflict when the main character eventually discovers they have to speak in front of a thousand professional adults at a conference. Or going to a party where the shy person causes a social disaster, could be the beginning of a book about a kid with social anxiety whose friends sign her up for running for student body president.
In Lies of the Haven, Mina wants to lead, but believes that she isn’t very good at it. She’s not very good at any of the tasks that the faeries expect of a good leader. Each time she tries to lead, she seems to turn everyone against her and so each step in the book is her trying but failing, even as the stakes in each situation rises. Its not until she learns some important things about what it means to be a good leader that she eventually gains the confidence necessary to become the leader that the faeries need.
By the end of your book, your character should have learned something new that will give them the strength to overcome their flaw and defeat the antagonist (usually the bad guy).
These ideas can be found in greater detail in many places on the web by doing a simple search, but I want to give a shoutout to where I officially learned it. You learn this and other important aspects about YA fiction writing from the Writing Academy.
Also I found this great source that summarizes the three act structure of story writing. Getting these parts down will create a story structure that will engage most readers.
Also, I’d recommend looking up the Hero’s journey as this is a standard story structure used very often in writing.
Again, I’d also recommend taking advantage of free writing sources such as Brandon Sanderson’s free online course on writing Sci-Fi/Fantasy.
***AND thanks to Katelynn for the awesome question! I hope you find this information useful!