Image wont enlarge on site

Hi guys simple question but it just doesnt seem to be working.
I have an image of a price list that I want to make larger on the site.
I have tried clicking and dragging the corners out and also clicking on the image/edit image button/advanced settings/under size typing in larger width and height/update. It enlarges in in the dashboard but NOT on the site. It’s still too small to read the price list. What am I doing wrong? (I dont know any htmal or css as yet but will learn soon).