Be punctual, dress like you respect yourself and this new job, role play answering some basic questions like "why do you want to work here"?, and memorize 4 great things about your self , 4 things that were hard but you aced and 4 examples how you finished projects and managed your time well. Have a resume if this isn't your first job. At the end of the interview say " Thank you, when will i hear from you"? Shake her or his hand if offered firmly.