The universe had more matter than anti-matter. We don't know why.

in case you missed PART ONE

The cooling universe.

The quark-gluon plasma cools to the point where they form Hadrons.

This is where we first see the imbalance of matter and antimatter.

This era starts at 10^-6 seconds after and ends one second after the big bang and with the event of most anti-matter matter pairs being impossible to create (on average throughout the entire universe). This is where the neutrino version of the microwave background was formed. However, because observing neutrinos is near-impossible with major detail we may never see it clearly. At this time hadrons annihilated each other and did not reform into antimatter-matter pairs with consistency. This marked the end for major amounts of antimatter.

For a short period of time leptons ruled all.

from 1 to 10 seconds leptons are the only matter-antimatter pair that can be made. They were in abundance and they were most of the matter in the universe. This like all the others did not last long. At 10 seconds they could no longer be forged from the average energy and annihilated each other until few were left.

Then photons ruled the world.

Photons become the dominant form of matter, but not for a long time would they travel far.

The nucleus formed and light was blocked.

Neutrons fused with all protons for 17 minutes in this phase. This produced hydrogen and helium-4. Electrons blocked Photons en masse. None could travel without being absorbed over and over again. This slowed them and trapped them.

Suddenly that stopped.

Electrons slowly lost energy during this and eventually lost enough to get trapped by the nucleus. This means that light was able to freely travel and it created the "cosmic microwave background" or CMB for short. This happened roughly 377 thousand years after the big bang.

This is the end of the Big bang Era.

After this the CMB is the only source of light, for over 100 million years. That's how long it took for the universe to cool down enough to form stars. Stars are made in giant gas clouds which slowly condense do to gravity. If it is too hot they simply move around to much for gravity to have any effect.

This is the very early universe, comment what else you would like to hear about below!

image sources:upload.wikimedia.org/wikipedia/commons/9/9e/Schematic_diagram_of_the_history_of_the_Universe.jpg
upload.wikimedia.org/wikipedia/commons/3/3c/Ilc_9yr_moll4096.png

and more reading

https://en.wikipedia.org/wiki/Big_Bang
https://en.wikipedia.org/wiki/Chronology_of_the_universe