4 states => 2 bits => 2 flip flops with a little bit of logic would work well for a synchronous debouncing scheme. i just did one recently and its pretty simple. if you dont want to mess with clocking, try one of the other suggestions involving schmitt triggering.
I am in high school, and I am definitely not in your shoes. I fundamentally believe that true learning is done by yourself. Teachers and forum members are there for guidance... If you are having trouble they are there to point you in the right direction not spoon feed you. If you think that you need help for a project at least show that you have put considerable thought into it. Here is where I thought I needed a little "guidance" with a large project and I think it should be an example of how to correctly approach someone for a little assistance. https://www.electro-tech-online.com/threads/camera-fpga-psram-interface-check.23395/