I have a dog named Daisy. She is in the backyard. She is very very lovable. She is a Beagle Mixed Lab. She barks at frogs, birds, people, bees, cats, squirrls, rabbits, cars, lawnmowers, etc. I would like help trying to make her quiet down some.

Barking is so tough to handle.
It's funny because Beagles are barkers and labs aren't, generally.
Dogs can learn 'no bark.' Mine all have but all also either keep barking (somewhat apprehensively) or woof through closed mouth, trying very hard to stop. I'm a lazy trainer.
It takes a ton of training. Distraction, command, and then praise. Over and over. With a tiny treat or not, maybe randomly. Bring a toy. Rub her tummy. Being on her back puts you in alpha position. Bring in inside.
When you issue an type of NO keep it short and sharp. Take a moment to stare down your dog. A dog is not a human.
But also no wheedling, no yelling, no hitting.

When you say Daisey is in the back yard, do you mean she is kept there all day long? A lot of dogs will bark out of sheer boredom. They want to interact. They are pack animals by nature, so being left on their own for extended periods is like you being isolated. They need interaction.

Barking can be fixed a few different ways. One way is to teach the leave it command, leave it basically means, stop doing what ever you are doing. So when they start barking, chasing things or even digging, you say the command leave it. Get his attention with a chew toy or a bone. And praise him when he stops doing what you don't want him to do.

Another trick is the spray bottle. I am not really a fan of this method, only because some dogs can actually become fearful, and I don't think a dog should ever be trained in fear. But if he doesn't become scared, just a quick, small burst of water to the face an do the trick while telling him to SHUSH or quiet in a firm "I mean business" voice. Of course I wouldn't suggest doing this in winter or colder temperatures.

If your dog is simply bored, a little extra exercise and play time can tucker him out, leaving him with no energy to bark at everything that casts a shadow.