You can watch the show on Fox on Thursdays at 8/7c, of course, but there are plenty more options in case you don't have a TV. fuboTV is one, while episodes move to Hulu the next day, as well as (with ads) on Fox's website.
And previous seasons of the show are streamable on Netflix, if you want to find out how Batman began before he currently begins. And you should check it out! The show has gotten more confident (and crazier) over the past few seasons, anchored by excellent performances from Robin Lord Taylor as the Penguin, and Erin Richards as the bananas Barbara Kean.
Villains, and a young Batman? What's not to love?