How can i make my girlfriend official horny?

Hey, i just turned 15. And me and my girlfriend are at that stage were we don't want to be virgins anymore. I've been thinking of doing a couple things, But it doesn't sound right in my head so i was wondering if someone could give me a thew tips on how to my girlfriend horny. she's asked me to have sex with her, and said yeah but i don't know how to make it fun and interesting. like should we go out for a movie first then back to my place? please comment back i need to know fast :)