I don't know where to started. This is for a java class if anyone can help me with this question. You don't have to do all of it. I just need help to get me started or help me understand what I am doing

Exercise 4 Create a project with a class called Box (w/ main) that contains the following instance variable: int size 0; Then add a method to this class named printBox with no parameters and void return type, that prints out to the screen a set of *(star) characters with size rows and size columns. Enter code in the main method to create a Box object, change its size to 5 (using the dot operator), and then invoke its printBox method. Run the program and fix any errors you may have