Animating

Hello! I am fairly new to Adobe Animate and I'm having some trouble. I'm trying to animate my drawing for a school project, and I've watched multiple videos on how to do so. It said to right click on the layer you want to animate and select classic tween, but it's not showing up. And when I reopened my drawing, I couldn't interact with any of my symbols. Nothing would highlight, and I couldn't select anything. Please help!