I am unsure if I adequately understand first electronics right. If I post a story on a writers website for free but also publish it through Amazon, will it affect me?

As you've guessed from the title, I'm writing a prospective email to venues, about hiring their venue for a day. I've drafted an email, but it just doesn't sound right so I would like some feedback. I want to get straight to the point, but I don't want it to sound to forward... I'm intending to c...