Remove Multiple Images Overflow From Margins

[DeborahLeeR]

Am new to Affinity (brand new, and baby boomer, so you may have to speak slow  . Using Publisher, I've created a simple one-page ad, 7.5" x 10"H to print on standard 8.5 x 11 sheet. Outside the margins are overflowing rectangles and other elements that need to be cropped out but need to retain the 1/2" white margin all the way around. Cannot figure this out and have googled best I can. Was told it involved picture frame tool and paste-inside, but...please help.

I'm attaching the image so you can see the margins, etc.

[firstdefence]

Press Backslash  \  on the keyboard to clip the canvas.

 

The Picture frame method, the page contents are grouped to easily move them into the picture frame, the picture frame was set to the bleed lines.