The Catholic saints simply subsumed the roles of the pagan gods that preceded them. For example St. Eligius took over the role of Vulcan/Hephaistos from the pagan pantheon. Just as objects, jobs and classes of people had patron gods, they now have patron saints. Just "venerate" (worship) your patron saint and you'll be fine! 🙄
A lot of "saints" weren't even real historical people. There's the above example of St Brigid. And of course, St Christopher.