My Ww2 Finds Where Can I Find WW2 Records?

Where can I find WW2 records? - my ww2 finds

I am trying to trace the history of my family, but it is difficult to prove. I remember my father told me that my great-uncle served in the 2nd World War I, and I wonder if he has no preference Irish, but English would help two, because I'm not sure if they still evacuated from Ireland or England. Thank you in advance.