Hello @awinneg,
Welcome to the Canvas Community!
Is your organization using Canvas Free for Teachers, a self-hosted instance of Canvas, or hosted instance of Canvas? The answer to that will help with some specifics for how to do what you are looking to do and also determine whether it is or is not possible (because Canvas FFT has limited functionality).
At a high-level, there is a lot of data available in Canvas but most of it requires the customer to extract/manipulate raw data on their own instead of using default reports that are built into the Canvas LMS or to use the API for real-time data and the exact steps vary depending on what data you want.
It is relatively easy to do something like generate a report for your "How many students registered for the course?" question but how will vary. For example, there is a report available within each Canvas (sub)account.
How do I view reports for an account? - Instructure Community - 109
Canvas Default Account Reports - Instructure Community - 387054
However, something like ""How many of those newly registered students have completed at least one module of the course?"' would require either using Canvas Data (https://developerdocs.instructure.com/services/dap/dataset/dataset-namespaces/dataset-canvas) or the API (check out the question at module progress for all students via api call - Instructure Community - 568203 as an example).
While not a complete answer, I hope you found this helpful and a way to get started. Maybe someone else can provide you with more guidance.
-Doug