Yes, you can hide the website until it’s ready in two ways:
1. The easy way to hide your WordPress website while you’re in development is to check the option “Discourage search engines from indexing this site” from Settings > Reading
2. Another way is to install a free maintenance plugin like https://wordpress.org/plugins/wp-maintenance-mode/
The plugin will let you customize the website but it will be hidden for the users and Search Engines. This is how the visitors will see the frontend:
One advantage to use the maintenance plugin is that you can collect emails until you finish the website and already have users for Email Marketing when you start your business.