What do you mean by " I really have no idea how to design them since its more of a code base programming language"? code-base as opposed to what? The first think you should do is to sit down and figure out the logic of the game, write out ideas, think of what ideas should be placed together into separate classes, and how should these classes interact. Do a lot of thinking and brain-storming before trying to write any code. You might want to sit down and talk to your teacher or a tutor to get more ideas, help and a starting point, or if you have specific design questions come here and ask them (we don't do well with very general questions as a rule though).
and now my new professor is asking me to create a 2d game using JAVA codes. The game is sepak takraw, the way i vision it is it a bit similar to a ping pong game but instead of a ping pong rocket an object that looks like a 2d human that can kick the ball. I really have no idea how to design them since its more of a code base programming language.