Get a professional, business-like haircut to go with your suit. You may feel silly when you first look at it. The whole rest of the world expects a haircut that matches the suit. If you are going to do this, do it right. If you want to speak with an adult, offer to make an appointment.
Adults are busy people.
Their time is valuable. Show up on time for your appointment. It is important to keep all of your commitments, both large and small. Adults notice people who do not keep small commitments because it often means the larger ones won t be kept as well. Speak clearly Speak as an adult would speak rather than using teenage slang.