Hello,
Thanks for submitting a question about temporarily deactivating your site. There are many different ways to do this. The BoldGrid way to do this could be launching a staging site with a maintenance message on the home.
There are WordPress plugins that allow you to serve a customizable “maintenance” page; this is arguably the fastest and easiest way.
There are also server-side tools you can use to redirect visitors to a maintenance page of your own making. Your host can you help you in that regard.
Best,
Christopher M.