Once you've planned out what you want to cover in your course and what you'd like students to get out of it, creating a syllabus is the next step. While this can seem like a daunting task, it simply involves translating the idea of your course into a particular format.
Great question! There's a few standard things that are important to have, but Penn State's Schreyer Institute for Teaching Excellence has a handy-dandy checklist covering these that is embedded here:
https://s3-us-west-2.amazonaws.com/secure.notion-static.com/03fbf120-681f-41b6-94c4-897cacf31261/PSU_Syllabus_Checklist.pdf
Because these are student-led courses, it might be a great idea to include some information that bolsters your credibility. Students, and any college-level administrators reviewing your course proposal, might be wondering why you're qualified to teach the subject you're teaching. Consider including a brief bio in your syllabus about yourself, experience with the subject, and why you're teaching the course. The best place to include this will be on your Canvas page, but we'll cover that later in the process if your course gets approved.
Be sure to include the following in your syllabus as well:
Here is the text for some statements required to be included by the University:
https://s3-us-west-2.amazonaws.com/secure.notion-static.com/9475cb7b-2ba7-4e0a-ae16-e5765ce43411/Required_Statements.pdf
Here is a document by the Schreyer Institute for Teaching Excellence that touches on great action verbs to use when writing your course objectives.
While the content of your syllabus is the most important part, be sure to be thoughtful about how you format your syllabus as well. From basics like consistent font and text size all the way to having an intentional order of sections, being thoughtful in how you design the syllabus's structure will make understanding your proposed course much easier.