Tips on my first time having ?

Okay so two years ago I told my best friend that I liked her, she liked me too and we stated dating but not long after, she moved to England but we still spoke every day and we saw each other every holiday and about 2 months ago we planned to have (first time for us both) when we see each other at the end of this August.. I guess what I really want to know is if there is anything important I should know to be prepared? Thanks :)