I am not much into the theory/not theory debate around the Theory of Evolution but there is something I really don't get into the narrative you are presenting.

The Theory of Evolution is a set of ideas that describe the world and allow us to make a sense out of it, like any other claim. The thing is, it's backed by a lot of other scientifical theories with which it perfectly fits (DNA, species, morphology). Plus, every evidence found so far doesn't contradict Evolution. Plus, it has allowed to guess what happened in the past (on a species characteristics, locations and dates), before we found fossiles exactly there.

It's largely enough to trust Evolution.

If you want to dive more into the question, I will be very cartesian, but I will tell you: we know absolutely nothing (well that you think and that you exist, great). Everything else comes either from experience or from what people say or write (let sum it that to "text"). You can't know what is true. Ultimately, it's a question of trust, towards people that don't know either, but trust too. When talking about reality, the only things you can check is experience. As a text with claims, Evolution isn't completely true, in the sense it's not complete. It doesn't say why this species in particular evolved this exact DNA part in this exact way at that exact time. But that's really a meaningless point. You will never find a text that accurately describe every single event in the world (or it would have to be the world itself). So the real question is how reliable, accurate and useful this text is in our understanding of the world. And the Theory of Evolution is an old boxer that beat every other competitor in one round during the last 2 centuries.