How do you know that protons exist and that stars are balls of hot gas like our sun? Theories of physics and astronomy tell us these things and many other things besides. You pick and choose the evidence that you want to accept according to whether it matches folk tales of bronze-age middle-eastern animal herders who were probably highly intelligent but had no conception of any of these things. They had myths that made sense to them but that make no sense in the light of modern physical knowledge.
I am a creationist as a result of studying scriptural history. Over 2000 years, 40 different authors wrote down the things they witnessed, without any contradictions, and without having conferred. This proves the coherency of canon to me. Prior to Moses (Exodus, chapter 2), there is mostly only oral tradition (which Moses compiled). Oral tradition may seem fallible but, in oral societies, it is taken seriously and even a secular story may go hundreds of years unchanged. In the case of Genesis 11 through 50, there is little reason to doubt the tradition. Abram was only born 4 centuries before Moses. With this much coherency, I am not going to doubt Genesis 1 throught 10 without definite proof that it is untrue. A scientific theory which uses only its own internal logic, no matter how well it describes the universe, does not explain it.
Evolution does not contradict creationism. Created things evolve. It is creationism which limits evolutionary theories to a time period. What happened before that is not the purvue of evolution as a theory. This is the purvue of geology, astronomy, ontology, theology, cosmology, etc.
Whatever terminology these sciences come up with, whatever processes they describe, there is no proof they always existed. This is the central issue. One can neither prove nor disprove the assertion that time has a beginning. One day, time began. See?