How to remove sidebar and increase primary width only on certain pages

Can you ascertain if the pages not using a sidebar are also using a separate Page Template? This could be achieved with custom functions (in a theme) or at the Page Editor.

Thank you for answering but I don’t understand what you mean. I think I have an idea, I remember with other themes when you click on “quick edit” on a page there is a Template dropdown with an option of no-sidebar. This theme doesn’t have that option. Is that what you are referring too?

Yes, it was…or then it is with the theme, you will need to ask theme dev.

general:

if you are referring to static pages, consider to create a page template for those pages without sidebar; basically just a copy of page.php, with the extra code at the top and the call of the sidebar removed;
https://codex.www.ads-software.com/Pages#Creating_Your_Own_Page_Templates

then use the page template specific css class (which gets output by body_class()) to add specific styles to stretch the content width over the available space; https://codex.www.ads-software.com/Function_Reference/body_class

Thank you alchymyth for your help! I am going to read through the pages that you provided and hopefully understand everything! I’m just starting to learn php, so hopefully it won’t be too confusing!

Thank you again!