Genealogy / Last name Confusion "Judah" [13]

Hello, I was just wondering lately, the last name of the Polish Side of my family is Judah and the average look to them is normal peach colored skin, brown hair, and quite tall. Im confused though because I could trace my family back to the WW1 Era and their all Roman Catholic, I was just wondering If you guys could explain why my family has a jewish last name but are catholics and maybe if you smart enough what genetics might be part of my blood with tall brown haired people in my family, like are they more closely related to Hungarians or something or just your average day Pole, thanks in advance, Hussar27.