Missing template dropdown in Page Attributes

I am wanting to make all of my pages full width, however when I go to the page attributes menu only ‘parent’ and ‘order’ are available.

I have used the free ‘radiate’ word press theme. I have managed to get rid of the sidebars by deleting the ‘side bar’ line on page.php and front-page.php, but I’m not sure what I need to change to make the pages full width.

Here is my webpage:
https://cpsportsmassage.com/

Also when I go on to the pages selection on the main menu, the home page is not on there, only the new pages that I have added are there, how can I edit the main homepage?

I would appreciate any help you can give me