Answer 1

if you want to do graphic animations with Java, have a look at the processing IDE (a coding environment for visual artist)
https://processing.org

If youwant to do animations with JavaScrip, have alookat p5js
https://p5js.org

If youwant to do animations with C++ have a'look at
OpenFrameworks
https://openframeworks.cc
or Cinder
https://libcinder.org

If youwant to do animations with python have a look at
PyGame
https://www.pygame.org

of the above, only p5js will work in Solo Learn Code Playground.