Without A/C you're never going to make your garage cooler than outside. What you want is to have the garage the same temp as the outside and it will be cooler because you don't have the sun directly on you.
Open your garage door and get a screen for the door. I have garage door up about 10 months of the year. I did have rabbit one time pop in when I came home and opened screen and was putting my golf cart in, he hopped in so quickly and I couldn't find him. I found him a week later when the smell was horrible. With screens you can avoid most creatures, snakes, gators, rabbits, bugs, etc. Also with the door up, it will give you privacy, and obviously keep out two legged creatures with sticky fingers.
You have the one piece screen that goes up, I have the horizontal that has 3' sections that slide separately by hand. That way I can open just one section to go in and out, and then close it behind me quickly.
Here's my garage and the door is open. You can't see in, you can't even see the car. Nobody or any creature can enter, and the garage will stay about the same temp as the outside air. That's the best you're going to get. A big fan will move air and that will cool your body to a certain degree.
I have my washer & dryer in the garage, in the back. I have a wire shelf installed above them for detergents and stuff. I also have this fan on the shelf and have it aimed in my direction when I working in the garage, it will help. It was about $35 at Walmart.
This one is $39 at Walmart. If you don't a have a shelf or a good place to place the fan, you can get a fan on a pole with a base and they can be aimed in any direction.