The concept you're referring to is known as the cosmic microwave background radiation (CMB). The CMB is not actually the light from just after the Big Bang itself, but rather the afterglow of the early universe that has been stretched and cooled over billions of years. Allow me to explain further.
The Big Bang theory suggests that the universe began with an extremely hot and dense state approximately 13.8 billion years ago. As the universe expanded and cooled, photons (particles of light) were emitted. However, for a very long period after the Big Bang, the universe was filled with a hot, dense plasma that was not transparent to light. Photons were constantly interacting with the charged particles in this plasma, causing scattering and absorption, which prevented the light from freely traveling.
About 380,000 years after the Big Bang, the universe had cooled down enough for the protons and electrons in the plasma to combine and form neutral atoms. This process is called recombination. Once recombination occurred, the universe became transparent to light, and the photons were able to travel freely through space without being constantly scattered.
The photons that were released during recombination have been traveling through space ever since, gradually stretching and cooling as the universe expanded. This is what we observe today as the cosmic microwave background radiation. It appears as a faint glow of microwave radiation that is nearly uniform in all directions.
While nothing can travel faster than light in the present universe, the expansion of space itself can cause regions to move apart faster than the speed of light. This expansion allows the CMB photons to reach us from all directions, carrying information about the early universe.
By studying the properties of the CMB, scientists have gained valuable insights into the early universe, its composition, and the initial conditions from which galaxies and structures eventually formed. The CMB provides a snapshot of the universe when it transitioned from being opaque to transparent, rather than a direct view of the Big Bang itself.