You can add widgets to the sidebar widget area at Appearance > Widgets > Sidebar. Once that’s done, go to each of your pages and set the page template drop-down menu to Full Width. That’ll ensure that no sidebar is displayed on each page you select this page template on.
Another option for more granular widget display control is: Jetpack Widget Visibility. This module will let you set positive or negative display conditions for each widget. If you’re activating Jetpack for the first time I usually suggest doing a bulk deactivation of all modules at Jetpack > Settings and then choose the modules you want to make us of.