In Jupiter X you have a highly customized website. You can change the layout of a page to have a Sidebar or remove the Title Bar for it.
But to have a Full-Width layout, changing your layout to No Sidebar and remove the Title Bar is a bad practice, because it adds an unwanted space around of your template:
To have a Full-Width layout on right way in Jupiter X:
1. From WordPress dashboard, edit the page which you want to make a Full Width.
2. From Page Attributes, choose the Full Width layout.
3. Update the page.