Home page divider problem

Hello,

My home page (https://yorksphilchoir.co.uk/home/) has three panels at the top of the page where the image slider currently is.

I used to have the first panel extended to fill the page because I do not use the other two.
After some recent complications the home page has gone back to default mode, showing the panel header box only on the left of the screen.

I either want to get rid of the panel box entirely or stretch the panel to fill the page again.

Can anybody help as I’m not experienced enough to read/write php.