Hello,
You can create a page and use “Post Grid” element in Visual Composer to show posts only from the specific category.
To show specific sidebar you need to create a custom sidebar area in Appearance > Widgets https://www.8theme.com/demo/docs/royal/#!/8_widgets_custom_widget_areas and then select this sidebar in your page editor in “Widget Area” field on the right side.
Best regards,
Jack Richardson.