What did the Big Bang look like?
no one is 100% sure, but....
Big Bang before Big Bang was just a giant singularity containing all the mass in the universe. Then in an unknown way the singularity separated, probably by dark energy, creating atoms and other particles that got separatated and creating the universe as we know it. How it looked is hard to answer but you could think of it like if the whole singularity got divided into trillions of small particles that later formed everything in the universe.