I believe there is a limited amount of free will and maybe what God knows is what is known as a pattern. But patterns can be broken. Not usually hard set patterns.
Lets take my morning routine. I get up and the first thing I always do is go to the bathroom to pee. Once in a blue moon something will disrupt that. A phone call, or my dog urgently needing to be let out. Most days you can definitely count on me going to the bathroom first. I do it without thinking. My bladder sets this pattern in motion. I could ignore it for some time but eventually I will have to go or my bladder will simply make the decision for me. All the free will in the world won’t make me not pee.
So life is the same way. We each have pretty much the same pattern. We are sent to school to get educated and then to get a job to survive. The need to survive sets many of our patterns in motion, but we each react to it differently. To some, surviving means clinging to someone else like a life boat, and to others it means doing it all alone and to others, it means having a large circle of friends to help along the way and some just choose to exist. All of these things are partially pre-determined by life experience and some by mental instability, but rarely is it all done by a whim.
So think of it this way. Lets say you have a large network of friends that you know better than their own mom. You decide to put them all on an island. You can probably predict their behavior in different situations and who would most likely group together because of the things they like, but it doesn’t mean you took away their free will. So think of God in a larger scale. With the ability to predict every thing every human being will do in their life time, but he never tipped the scales one way or another. Never intervened with the exception of deciding when it is your time for you soul to leave your human body because he didn’t give us unlimited life.
Or another way of looking at it, is humans are one large living organism. Some are cancerous but we all work for the goal of making this planet work. (Except the cancerous ones) Where we go and what we do is someone pre determined by where we came out. Like a liver cell will be liver cells, and lung cells will be lung cells. Billions of cells in every organ, and any one of us may decide to go bad. That is as far as our free will goes.