After buying 'CSS in 44 Minutes' and going through the materials, I have to say, this is a good place to start if you want a nice intro to CSS animations that you can implement right away in your project.
I'm trying to get away from using Bootstrap for performance sake and I was pleasantly surprised to find out I can do such slick animations using CSS now.
I'm really enjoying learning more flexbox and soon Bulma framework!
FYI: I am not affiliated with the product whatsoever, I just bought it for myself and found it really helpful. Check it out yourself and report back!