For such a basic question you should go to Daynhauhoc.com. This forum lacks of volunteers to assist newbies like you with IDE tools such as Netbeans, eclipse, etc.
I myself always discourage people like you to use IDE. So, I strongly recommend you to start with the basic JAVA using any plain editor (e.g. notepad, jedit, etc.) and use a CMD window to compile, to execute the codes. That is the best way to become a REAL developer.