the Universe begins by popping into existence with simple hydrogen and some helium

Not quite. The universe begins with a (mostly) homogeneous soup of sub-atomic particles that are far too hot and have far too much energy to be able to form stable atoms, not even simple ones like hydrogen -- they'd get blasted apart again just as fast as they formed. It takes some expanding and cooling until heat/energy levels drop low enough for electrons to start orbiting protons and form atoms. (Not even protons could exist in the extremely early universe -- fundamental quantum particles coming together to form protons, neutrons, and others would have been quite the development just a bit earlier in expansion.)

Hydrogen and Helium are gases that are able to carry sound.

And they did. This isn't just speculation, we can actually see it!

The sound waves in this very early universe (called baryon acoustic oscillations) went on to develop into the high and low density parts of the universe. They effectively 'froze' in place once the gas became too sparse to carry sound waves, and the pressure waves that were left at that moment formed regions of high and low pressure, high and low density. High density areas formed more stars and more galaxies (and attracted more dark matter) than low density areas. The sound waves in the early universe are actually what created the large-scale structure of the universe as we know it today.

And that's not just hypothetical speculation. These wave patterns have been detected and have been known for decades. Yes, the early gas-filled universe was very loud -- and we can still see that today!

"And on the first day the flying spaghetti monster ripped the most epic fart ever and reality was born"

Obligatory Karl Pilkington:

was it a big bang or did it just seem big because there wasn't anything else to drown it out at the time?

Think about how high pitched our voices would be at that event, assuming we survive the heat.

If a tree falls in the forest and there's nobody around to hear it, does it make a sound?

Some argue it does not, since sound is. An interpretation of pressure waves in a particular frequency range.

I personally believe it's still sound. Even if it's not heard, it can be recorded and replayed, therefore any time there are pressure waves within specific range they should be considered sound. If you play music on the radio and nobody is listening, it makes a sound, but if you transmit it only using AM/FM it does not make a sound.

Having this definition down, yes, it must have been one Hell of a bang, but so what?

If a bang happens in the universe and no-one is there to hear it, does it really make a sound?

Big bang if true

The entire universe was opaque to light for a while

Where did the hydrogen and helium come from?

Yeah but nothing was there to hear it