I am confused as to how copy code for a game, Connect 4, onto Eclipse and make it work.
The problem is I am not sure whether to create a new 'Package' and paste the code there or make a 'Class' and paste it there or whether it's a combination of both.
I would suggest on Eclipse, you create a Project, then a package, then a class inside that package. You can copy and paste lots in to Eclipse; you can even copy an entire .java file into the right part of the workspace folder and Eclipse will recognise it as a class. It will show up errors like wrong package name, and allow you to correct them.
I would suggest you create a more object‑oriented version of that code, however.
Also package names should start with small letters. In which case Default will turn into a keyword, and the code won't compile. Try a different package name.
If your class is java class you can directly paste after creating project and package using eclipse. Eclipse has very good features of automatically correct the errors however it may ask the classes your file requires in class path.