You can enter a different background in the template ?

More details please and which background do you mean?

hello, I want to prepare a template white and I would like to clear a background like this
www.zumbaparty.it/socialmagazine/

You can set the background via Template customizer.
If you want to have another background you have to customize the theme and add your own css style to th file > css / custom.css

We are committed to help you with any type of support query, however we can't provide extensive help in terms of customizations. In general customizations may look simple but you will require solid knowledge of web technologies and programming skills to do them or hire a professional who can do it for you.