A bronze medal test costs around a tenner and doesn't require any special outfit, though you should wear a dress or skirt not trousers.

Your teacher will explain everything as the exam day approaches and will probably give you some dummy runs.

For Bronze, you'll dance two dances, usually waltz and quickstep, or cha cha and jive for latin. You'll probably be partnered by your teacher so there's not much chance of everything going haywire, and no-one expects perfection at that level. Just moving in time with the music is enough for a pass but you'll no doubt be aiming for a high percentage score. Good luck.

PS
To answer your other query, I'm from England but it's a long time since I was 13.

Howard