Confused on manga sizes in the us

Hello, I would like create a manga styled series and I saw that in north america the standard sized volume is 5 by 7.5 inches. In clip studio paint, there is a bunch of templates that are modeled for Japanese issue sizes(like A4,B6, ect) but I don't see any models for sizes in the NA. I saw a template at a printstore in my city which seems good however it's missing the crop marks for the printer (are they necessary?) So I would like to know what do I type for the canvas size, trim line and the inner border