If you don't own/can't afford a suit don't sweat it. Presentation is what matters more (clean, tucked in, good communication skills, etc). Resumes are really helpful but if you don't have a formal one try to write/type/email the activities that don't appear on the candidate activities (leadership seminars, all conference sports, etc). This is your one opportunity to get additional info to the admissions board outside of the max word essay and bubble-in activities. If you forget to add 10th grade whatever (or it doesn't come up) email your BGO the info and a description ASAP. I tell candidates I will do an immediate rough draft of the interview then I give them a few days to reflect on the interview and if they think of additional information to please send it along. I do not share the write up with them. Sometimes things get left out without a resume road map so try to at least jot down for your own use a list of things you've been involved in so you can make sure these things are discussed.