Reading professional scripts is an essential way of honing your skills.
Check out these reputable script competitions. They can be a great way to get some recognition but they are very competitive. Consider whether your entry might benefit from some professional analysis before submission.
Reading and studying professional screenplays is a great way of learning how the best writers do it. I don't recommend looking at viewer transcripts as these are usually unformatted and don't do justice to the material. Here are some good places to find copies of your favourite movies and television shows.