Java doesn't recognize the gson library on the dowloaded starter kit

I tried compiling the starter kit files for java, and got a bunch of errors that I assume are because my computer doesn’t recognize the gson library.

My computer uses osx. I looked on stack overflow for an explanation on how to download the gson library. The process was pretty involved and requried stuff I don’t understand like copying repositories and maven. I feel like there is an easier way. Maybe I just have to update java?