Check publication titles in Ulrich's
If you have a journal and you need to check if it is peer reviewed, use the Ulrich's Periodical Directory database.
Enter the name of the journal in the search bar, then look for the little referee's jersey icon or the line that says "Refereed: Yes." "Refereed" is just another way of saying "peer reviewed," so if you see either or both of those things, your journal is peer reviewed.
If you don't see the icon or if the description of the journal says "Refereed: No," that journal is not peer reviewed.