There are lots of places online that have free but questionable screenplays to download. They might be illegal copies or fan transcriptions of what they saw and heard on screen.
To learn what the masters do, it’s a good idea to study their work not the interpretation of a fan watching the finished movie.
I have purchased a few scripts from there and they are great. Get some of your favorites. Study them. Collect them. Enjoy the art of filmmaking in a different way than you have before.