Search online for Project-Based and various performance Rubrics. Examine them for content and structure. Take notes on common elements. Start here with a basic rubric. Check out this website and its articles on Rubrics for Project-Based Units. Finish by reviewing the resources and sample rubrics.
In the next activity you will be evaluating sample Project-Based Units. Select and/or modify a rubric you would use to determine the quality of a Project-Based Unit.