Pride came from Lucifer who had freewill. Before he fell he was not yet in heaven for those in heaven are there permanently. Once in heaven always in heaven.
So he was tested just as Adam and Eve were tested. But just what this test was we do not know since we were not told. But it was the sin of pride that he committed because he didn’t have a body, he was a pure spirit. So the sin had to be of the intellect and will, which fits pride.
When he is described as falling from heaven, the heaven mentioned meant somewhere above earth in the upper sky since that is the understanding the bible writer would have at that time of the world. But in reality, it wasn’t the heaven as we understand heaven where the saints are.
So he didn’t really fall at all, because again he is a pure spirit, and spirits do not have any weight or gravity to work on and pull them down. By fall it meant that he fell from God’s pleasure and goodness. It was then that hell began, for hell is to be seperated from God.
I believe the acount of Satan’s fall is in the Acts.
May God bless and keep you. May God’s face shine on you. May God be kind to you and give you peace.