'Show don't tell' is the most common piece of writing advice. So, we want you to show not tell us about your character's feelings when they got their letter!
Without naming any emotions post at least five images or sentences about what your character is doing or thinking or saying about getting accepted into magic school. How's their body language? What's going through their head?
Sonora is an RPG site of all original characters. If you have not decidded what your character will be like yet, you can use a favourite second generation/background character from HP, or think about what your own reaction would have been like.