Google to find example plans. There's mountains of stuff online.
All business plans follow a similiar format:
Executive Summary
Management Team
Operational Plan
Marketing Plan
Financial Plan
Appendices
A well researched plan for a production company will show that you can start without investing a single cent. The contents will vary somewhat if you're doing a plan for a feature film vs. a production company.
No more than there's a template for writing a script.
There is a format that you can easily find online, and if you want details try to find a copy of 'The Successful Business Plan' by Abrams. It's a standard in a lot of business classes around here, and our SBDC has some copies. That's where I found one to borrow a long time ago.