What to wear to a wedding?

B

So I got asked to be my friends date to a wedding in July. And I know it’s a long ways away still but like what do I wear??? It’s an outdoor wedding most likely and it’s out in the country. Like a dress obviously but like - short? Long? Fitted? Flowy? How high should my heels be?? All I know is not to wear white hahaha

The only wedding I’ve been to was a fall wedding that was in a bar or something, it was years ago so I wore a fitted black jumpsuit with gold heels