The answer really depends on what we mean by God's plan. If that means God has planned everything out in my life then yeah I suppose there would be no free will. I don't see that as the case though as omniscience, specifically foreknowledge, does not entail direct causation and so the future God has foreseen is what we have chosen to do.
If God does not force human behavior as a result of knowing it we act of our own will and how we choose to act, hence free will. In that sense free will is balanced with omniscience (foreknowledge).
Yes, but you wouldnt have even been born if not for a countless number of very small "free will" decisions made by a countless number of people each and every day in the lives of countless generations prior to your day of birth. Any one of those decisions goes differently and you never make it here. nor do your children, or your grandchildren, etc.
I'll just take one isolated decision, for example. When your mother was ten years old, one day she crossed the street (I dont know anything about your mom, but I think it's a safe guess she crossed the street once between her 10th and 11th birthdays). A stranger makes the "free will" decision to run a red light and take his eyes off the road for a moment to adjust his radio, or to sneeze, etc. He strikes and kills your mother at 10 years of age. She therefore never meets/marries your father and never conceives you.
Any such decision could have been made literally countless number of times by countless numbers of people in any day of your mother's life resulting in her not conceiving you.
The same goes true for your father, and your grandparents, and your great-grandparents. Hell, one of your ancestors (I dont know your ancestry) could have made the free will decision to ignore the advice to duck during a moment in the peloponnesian war and been struck and killed by an arrow, prior to him meeting his future bride and conceiving your ancient ancestor!
Your parents could have made a free will decision resulting in a completely different genetic make-up for you, and hence you wouldnt have been you. You could have been the opposite gender, you could have had down's syndrome, you could have been a foot and a half taller and a superstar basketball player. Your genetic make-up would have been completely different if a different sperm had fertilized a different egg. For example, if your dad had been busy at work the night you were conceived, so they didnt have intercourse that night, and they didnt conceive for another month (and hence a different ovulatory cycle), it would have been an entirely different egg, as well as most certainly a different sperm.
So you cant have this sort-of loose freedom of choice if there is any sort of plan involving you, because you wouldnt even exist were it not for a pretty much infinite number of decisions going just right up until the day you were born. Free will cannot co-exist with omniscience.