Wedding Makeup What Do You Wear To A Wedding (& Makeup)? (Females)?

What do you wear to a wedding (& makeup)? (Females)? - wedding makeup

I am wondering what clothes to wear to a weding and what the makeup, I'm not going to a wedding since I was small and I do not know what things should be. It is an informal wedding during the day in May and I am 17 years old, with brown eyes and caramel skin.
I want to look good, but comfortable and even with makeup. : D