Hello Yitzchak,
In the Theme Options > Sidebars you can add customized sidebars / widgets areas.
These areas are automatically added to the areas list in Appearance > Widgets.
Then you have the following options:
1. Set a certain sidebar for a page type (for example, set the sidebar for all post page etc).
This you can set in the Customizer > Page Layouts.
2. Set a certaiun sidebar for a specific page.
This you can set in every page > Sidebars panel.