Aaron Blaise, like you already heard. If you're a beginner Howard Wimshurst has a really good intro course. If you already have some experience I'd recommend looking for a more specific course, like creature animation or effects animation, or looking for a community of animators that can give feedback. Again, Howard Wimshurst has a nice public discord server. Proko 2.0 doesn't seem to support video from what I can see unfortunately, so you may have to look elseware for dedicated animation feedback

Aaron Blaise! Creature Art Teacher is his website. Memorial Day sale is going on now. He has lots of videos, including a Fundamentals of Animation course, I believe. Also Character Design Stephen Silver is also good if you're into Character Design for animation