help with J++

I don't know if this belongs here or in C++, becuase I dont know shit about these languages.

Can someone explain to me how to make a square on J++, so I can understand the basics of it.
Then you need to put it in HTML, so you can view it in java.
I really don't know how to do this shit, it is so frustrating, im completely lost!

 

cmon ppl, I really need help, it's for school!!!