For thousands of years man has had a strong conviction of the importance of knowing how to distinguish between good and evil, the most logical thing would be that if we know two aspects of this world such as good and evil, then perhaps we could have the free will to choose which way to walk.
The way in which man has been organized throughout history has been able to emerge different forms of societies, which have dictated a model of life where you can distinguish the rules to know who walks the path of evil and who walks the path of good.
The human conscience takes an enormous protagonism, since many times man acts in a bad way without knowing or being aware of the damage it can cause, however it is very difficult to dictate by the laws of this society when one acts under conscience and when one does not act consciously.
If we derive the fact of our thoughts, they will always have the free will to decide about what is good and what is bad, however the moral fear that accuses us for having executed an action that can bring bad results stops us to execute it. In the case that our thinking does not have self-consciousness and we end up performing a bad action, we will have to answer to the moral laws of the society of the day.
It is important that our thought can have the free will of selection to be able to execute the choice of its path, be it good or evil, since what is bad during many years later becomes good, and what is good becomes with the passing of the years in actions that are considered bad. Only our conscience will be able to react through the process of free will what is good and bad regardless of what our society dictates.
God has placed his law in our conscience, for that reason we can know what is bad and what is good. It does not come from our intellect but from God's law, that means that what is good has already been defined by someone else, and what is evil as well.
For that reason when we do wrong, we are violating our conscience, but more than that, we break the law of God and that is sin, something much more serious to think and act.
Society calls good evil and evil good, they always create immoral "laws" to justify and satiate their sinful behaviors.
By the way, answering the initial question of your post, we are not free to choose, we must learn to do the right thing.
Greetings