You can disable your storefront while making changes or updates by putting your Uscreen site in Maintenance Mode. This will allow you to temporarily display a maintenance/under construction message so that customers cannot purchase or view your content during this time.
NOTE: Maintenance mode is probably only need if you have an active customer base. If you are currently in the beginning stages of developing your storefront, you do not need to use maintenance mode, because customers are not actively looking at your site.
Navigate to Settings > General Settings and toggle Maintenance Mode. The below graphic is what will be displayed in the center of your page when Maintenance Mode is enabled.