A lot of people dismiss evolution without truly understanding it. I know before I accepted the science behind it I was one who rejected it. Then out of a personal need to know I dug into it, began to see how so many fields of scientific study both within the biological fields and many others seemingly unrelated. So it might be helpful to start off by working with what "theory" actually means in scientific circles as opposed to everyday use in laymen terms...
A “theory,” in scientific parlance, is best thought of as some extremely well-supported body of knowledge which can explain the behavior of, or relationships among, certain objects in the universe. One example of a scientific theory is the "germ theory of disease." This is the theory that some germs make humans sick. We take this as an obvious fact now, but just several hundred years ago, many attributed disease to evil spirits and other causes that seem strange to us now. Another example of a scientific theory is plate tectonics, which is the idea that the surface of the world is divided into a series of plates that interact at their edges, causing the formations of mountains and volcanoes, as well as triggering earthquakes. (It is probably worth noting, again, that not so long ago in human history, volcanic eruptions and earthquakes were sometimes attributed to supernatural forces). So, you can see that the scientific usage of the word "theory” is very different from its usage in day-to-day discourse, where it indicates a hunch or poorly formed idea (e.g., that the Cleveland Browns are going to win the Super Bowl next year).
https://www.digitalatlasofancientlife.org/learn/evolution/https://youtu.be/Yjr0R0jgct4