Here’s a good video walking you through creating a business plan for your auto repair shop:
Here is the template he goes over in the video:
https://www.projectionhub.com/business-plan-templates/auto-repair-shop-business-plan-template
More sample business plans:
https://www.bplans.com/auto-repair-shop-business-plan
https://www.tekmetric.com/post/auto-repair-shop-business-plan-for-shop-owners