remove 2nd column in pages

Hi. All of the secondary pages have two columns by default, containing the Search box, Categories and Archives. How do I remove this completely from all secondary pages, so that they just have one column?
Optionally, how do I customize the contents in right column?

 

Hello,

Go to the Pages > All Pages in your dashboard and then edit your existing pages
and then select the "fullwidth page" Template from the Page Attributes section.

See the image for reference






Do this for all existing pages, this will solve your issue.

 

Thank you!