For Sidebars, you can set the Customizer > Layout > Sidebar for different areas. So you can change the Single Post Sidebar Layout to Content ( no sidebars )
As a minimum i generally have 40px Desktop padding and 20 to 30px Mobile Padding. ( They can be set separately in the Customizer by selecting the mobile icon beside the option ).
You can increase the left/right padding to a much larger value in the Customizer to extenuate the wide elements …. however this will also affect the padding on the Post Archives.
If you want to increase the padding to do that, then share a link to the site so i can provide a little CSS to correct that on the archives.