https://www.udemy.com/course/principales-to-2d-animation-frame-by-frame-animation/

Here's a comprehensive guide for beginners in ANIMATION. You will learn the ANIMATION  PRINCIPLES you need to animate objects, text, and even characters. If you want to learn  animation from scratch, you can start right here with this course. I designed this course for  beginners, so if you've never heard of a keyframe or don't know what a timeline is, then this  course is for you. This course is Animation 101. I also believe this course will be excellent for  anyone with a vague idea of animation, someone who is new to animation and uses software  to move elements but truly wants to understand the fundamental principles to take  animation to the next level.  These fundamental animation principles will prepare you for a career in animation. You'll learn  step by step how to create realistic and engaging motion; moreover, you'll understand why  certain specific animation techniques effectively bring objects to life. And most importantly,  you'll learn when to apply them to your work.  In this course, I use Clip Studio to teach you animation. You'll study classic animation, frame  by frame, hand-drawn. It's the best way to learn animation principles. And don't worry if you  think you can't draw, we'll work with basic shapes to animate - to breathe life into these  shapes.  This course starts by teaching you how to animate with just keyframes; it will guide you step by  step to animating a character jumping. I've structured each lesson to be neither confusing nor  overwhelming. As I've made applying the principles very simple, you'll have the opportunity to  truly grasp the concepts without worrying about drawing skills, working with advanced  symbols, or complex structures.