No, science does not know or claim to know the beginning of the universe. The Big Bang theory uses math to explain the probable physics after the Big Bang but not the Big Bang itself. See Planck Time.
Science doesn’t “know” anything. It’s a model for deriving information. It’s not a religion.
Also, your statement that there’s no science involved in the Big Bang theory is nonsensical. Math is used for measurement, but the method of questioning, creating a hypotheses, collecting evidence, testing and so on is exactly the scientific method.
The thread is not about faith, it’s about science. Science is not the antithesis of faith. As a matter of epistemology, natural faith in the truth of the philosophy that nature is fixed and regular in its operations underpins all science; the truth of which cannot be demonstrated by the scientific method.
Yet you mentioned faith first. Science does not deal in “truths” as religion does. It is a method for collecting data, measuring, and evaluating it.
Because data can be incomplete, corrupted, or not measurable by current tools, the conclusions derived from the data may likewise be erroneous. Some conclusions have a great deal more data and experimentation to support them, like the the theory of gravity, which we often call “law” because of the degree of confidence in the data.
But any law or theory of science can be modified, redacted, or even completely discarded if other, compelling information comes in that can be demonstrated by the scientific method.
That is the difference between science and faith. The my knowledge, your Catholic Church can never receive new information that suddenly conflicts with the truth of the Virgin birth or that Jesus is God. Religion makes claims for itself and its authority on truth that are considered permanent, unchangeable.
That is opposite of science. It is also why I think many theists claim there’s no conflict between religion and science because they operate in different zones. Religion deals in certitude, science deals in confidence levels, which can frequently change.