InfoPath Dev

I have created a Course Registration form in InfoPath 2013 from a Calendar list in SharePoint 2016.  On this form, I have two cascading drop downs, Course Name and Start Date/Time.

On the Course Name dropdown I would like to see only today's and future courses.

 

You can do that with a filter - when you select the CourseName field you can click to add a filter, and then select Start Date/Time is equal to or greater than, then in the third dropdown, select the option to use a formula. You can use the now() function to get the current date time.