The Big Bang was an expansion, and perhaps creation, of space itself, not like a bomb explosion in which matter and energy go into already existing space. There is evidence for several stages of the Big Bang, including a stage before molecules and atoms existed, a stage when some current basic forces were merged, an ultra-fast inflation of space, etc. Less than 1 / 10,000,000,000,000,000,000,000,000,000,000,000 (10 to the power of minus 34) of a second ago current ideas the ideas become without foundation.
There are various ideas as to what was before the Big Bang. Apart from "God did it", for many years physicists have been juggling many ideas including these:-
(a) Energy/matter has always existed eternally, (like God is supposed to have done).
(b) The laws of Conservation of Energy/Matter might noy always hold.
(c) There were "Big Bounces" of the universe contracting then expanding.
(d) The Big Bang created many universes having different physical laws. (These "multiverses" are different from Hugeh Everett's multiverses that are created with every quantum observation.)
(e) In Quantum Field Theory which is well established, energy is always coming into existence from nothing for a short time, and that was the start of it existing - Laurence Krauss often expounds on AUniverse from Nothing.
(f) Physicists are very aware of the contradictions between the well established theories of Quantum Mechanics and General Relativity gravity, so a new theory is needed.
(g) The energy of creating of matter is counterbalanced by its gravity. (But I don't get that!)
(h) There are mind-bending paradoxes of Black Holes.
(i) If the Big Bang created time as well as space, then "before" that is meaningless, because that is assuming a concept of time but time didn't exist.
(j) If near its creation time was much "slower", then one might never reach its start. Rather like trying to get a finite away if distance keeps getting smaller exponentially. Or like knowing that 0.5 + 0.25 + 0.125 etc to infinity never reaches 1.
and so on.
But the above isn't related to Darwin's Thoery of Evolution by natural selection. (As for the common objection "its name admits that it's only a theory", unfortunately the word "theory" can either mean an idea such as a guess, or what happens as shown by huge amounts of evidence - evolution is the latter.)
A main proponent of the bible's Genesis being literal from abnut 6,000 years ago are Kent Hovind (and his son Eric), which is an anagram of Viced Rhino who is a YouTube regular correcting numerous Kent's misleading statements about science. Another main proponent of literal Genesis is Ken ham of Answers in Genesis (AiG), and Paulogia often refers to "Ham and AiG" (ham & eggs)!
Kent and Ken say that Noah's Flood actually occurred about 4,000 years ago. As that supposedly killed almost all of life, the current huge range of animals must have developed from the relatively few "kinds" (unclearly defined) in a period of time much much shorter than the billions of years of the theory of evolution.