Creating a strong story conflict starts with your protagonist and antagonist. The sample section below of How To Plot Your Novel: From Idea To First Draft shows how to do that.
But first, a few quick tips.
Life Is Hard
Make sure life is hard for your protagonist. Choose a goal that's difficult to reach. And remember, if you're writing a novel, the goal needs to be challenging enough that it takes the whole book for the protagonist to succeed or fail.
Strong Antagonist = Strong Story Conflict
Also, a strong story conflict requires a strong antagonist. Your antagonist's one job is to push against the protagonist. Make sure your antagonist is tough to beat and has a deep desire to achieve their goal.
Learn more on your main characters and plotting your novel in this sample section from How To Plot Your Novel: From Idea To First Draft:
To find out more about the course click here.
Good luck with your writing!
P.S. Looking for more help with your novel but not sure about an online course? You can get free story structure worksheets here.