One of the easiest ways to verify sources is to take the title of the source and put it into the library catalog or Google Scholar search.
As mentioned before, this can be time consuming especially if you have multiple sources that you need to verify. Additionally, AI can produce citations that may contain partial truth in that the title of the article may be correct or close to correct, but the journal name is incorrect. Or, an author may be correct, but the title of the article is incorrect.
Save yourself time and start with library resources or you can always check with your librarian to get help verifying sources.