I'm going to audition for my high school play this year (suggestions)?

Choose a monologue that speaks to you. Let the character meet you, not the other way around. This simply means that you shouldn't choose a monologue that you have to work hard to really understand. Choose one that you just get and that is appropriate for the type of play you're auditioning for. Is it a comedy? Is it a tragedy? What era is it from? Is it Shakespeare? Choose a Shakespearean monologue. Is it contemporary? Choose something in the here and now. When you walk into the audition room, don't forget to slate. That is to say, don't forget to say "Good afternoon, my name is _______, I am auditioning for the part of ______, and I will be performing a monologue from so and so's _______" When doing the monologue, choose a focal point that is behind the auditioner so that your face is full front to them. DO NOT stare at them. That will make them uncomfortable and it is bad technique. Unfortunately, there are just too many monologues and factors to give you examples. But I would suggest search the monologue websites and when you find one you like, READ THE ENTIRE PLAY. This is incredibly important because it informs your choices.