Try arnb.org (see link 1 below). They have a good listing of events in the area. You can see the free schedule, but you need to subscribe to see the venue info. It costs only $4.99 for a month.
There are some regular events that happen every week - Marc Savoy's jam in Eunice on Saturday mornings, Fred's Lounge in Mamou on Saturday morning/afternoon, Liberty Theater show on Saturday evening (Eunice), Chris Miller's regular Wednesday gig at Loggerheads (Lake Charles), weekly jams (not sure what days/evenings) at Vermillionville (Lafayette), Rocky's (Eunice), and DI's (Basille), . Then there are a number of venues that regularly book Cajun music -- Blue Moon Saloon (Lafayette), Artmosphere (Lafayette), Whirlybird (Opelousas), Pont Breaux (Breaux Bridge), Prejean's (Lafayette), La Poussiere (Breaux Bridge), Vermillionville (Lafayette), Randol's (Lafayette). If you check the websites and/or Facebook pages for these venues, I'm sure you'll find more than enough to keep you busy.