Guaranteed your heart will be racing since its your first, so keep calm and just like flirting go with the flow. You also know that it will lead to sex, so make your self and the girl comfortable as much as possible and go for gold.
It helps complimenting the WL so she will be more open to providing you with additional extras that she won't offer to most other punters.
Be clean and don't be a smelly cunt. That's a turn off for anybody.
All the best bro.