I often cut my own hair. The big thing is to be clean. Get a friend to trim the ends of the hair or pull it back or smooth it back.
Look through your closet, find a pair of Khaki's or black pants. If you don't have either, do you have very dark jeans?
Worse comes to worse, go to Goodwill, you can usually find a pair of dark black dress pants cheap.
All you need then is a button up shirt in a solid color and an iron.
Dark socks, dark shoes, dark pants, lite colored button up. Trim hair yourself, pull or slick back if too long to cut.