Well, lesson one is complete, you learned they don't like shotguns!
I just went to another unsuccessful Hoot Hike event over the weekend. Lesson 2 is realizing these animals are built for stealth and do not really want to be seen. This will mean much unsuccessful owl hunting.
You can call Barred Owls with recordings. This doesn't work for all owls, but many of them do respond if you're lucky. Some caveats though. December through March is breeding season in Florida. Barred Owls WILL go after you if you tick them off , and they have lots of pointy bits. They're territorial year round, but especially then. They're less likely to show up during mealtime, which for a Barred Owl is 8pm-5am. You might do better around the start and end.
Caveat 2, of a bird is looking for you, it's not looking for food or sitting someplace it knows is safe, it's out looking for a potential enemy and is dropping what it's doing to do that, which you know isn't the case but it doesn't. Don't over call because you can stress out the owls and anything that knows it's prey for owls. Especially at night, animals need those calories to survive. Birds have high metabolism. You can kill birds if you stress them too much.
Lesson 3, Barred Owls hang out up high. Since their vision and hearing is much better than yours, they don't need to hang out low where there's more danger. Barred Owls hang out 15 to 40 feet up in trees. Point those eyes up.
That should get you started. You should be able to find some videos on YouTube to show you good tips. Also, I just Google "owl events near me" every so often and you can find Hoot Hikes, banding events, animal meet and greets, all sorts of stuff. Those people can tell you what works in your specific area.
Hope that helps!