If you like to set big writing goals and then dive in, you might want to check out the Script Frenzy event that runs April 1-30. Script Frenzy is an annual event sponsored by the nonprofit organization the Office of Letters and Light to encourage creative writing.
The goal is to write 100 pages of a screenplay, stage play, graphic novel, or TV script, all within that 30-day time period. If you reach your goal, you get a certificate. You can write a screenplay yourself, or team up with a partner and work on it together. Anyone can participate. There’s even a Script Frenzy Young Writers Program for kids who are 12 or younger, with classroom resources for teachers.
The Script Frenzy website has forums and resources for writers, like links that you can use to see sample scripts. There are also some regional events where you can meet with other writers if you want some company or encouragement. Note that this is a writing event, and the focus is writing, not on how to publish your work.
Thousands of people participate in Script Frenzy each year. There’s no charge, but since it is run by a nonprofit organization, they happily accept donations.