Change one picture on my website + make a support page on my website

I want you to replace one image on my website, and also make a support tab, where people can create an account with their email address. They should be able to make a support ticket, where they can give me questions. I should have a backend, where I can answer their questions. The support system should send an email when I answer a question, so they know that they have to log in to see the answer.