Enter your code in the appropriate .java file. This repository has two default .java files - Program1.java and Program2.java. You can rename these files if you want to, but be sure to update the name of the class in the file. You can add additional .java as well.
To run your code, hit the F5 function key on your keyboard (you may need to hit fn + F5, depending on your keyboard configuration). On the command prompt at the top that appears, enter the name of the program you want to run. For example, to run Program1.java, hit F5 and then enter Program1 into the prompt.
If you can't commit and push, be sure to set your git config settings
git config --global user.name yourGithubUsername
git config --global user.email yourGithubAccountEmail