There are lots of resources out there (besides our own tutorials) for learning ScreenFlow. Here are just a select few:
Mel Aclaro's Udemy course "Beyond PowerPoint: Teach Online with ScreenFlow for Mac" – $49
Learn essentials of video screen recording so you can digitize your knowledge, flip the classroom and teach online now.
Amani Channel's Udemy course: "Screencasting: Tutorials | Courses | Videos | Made Easy" – $99
Learn how to master ScreenFlow 4 for Mac on this Screenflow tutorial course.
Philip Ebiner's Udemy course: "Screenflow Basics - Screen Recording Made Easy" – $49
The complete and easy guide to using Screenflow for screencasting, tutorials, online courses, video production, and more