I assume you're referring to this step in your rapid developer course?
https://academy.mendix.com/link/modules/79/lectures/659/2.8.3-Starting-a-New-Sprint
While it may no longer be called the planning tab (and this text should be adjusted – there will be space for feedback on the course at the end of the course, or you can send your feedback to academy@mendix.com) the screenshots in that step of the course show the correct places to be and how to finish your tasks, so you should still be able to progress.