The information from the redshift  of galaxies tells us the galaxies are moving away from Earth. Or more precisely space is expanding

You get the idea of the expanding universe by inflating a balloon. Marker pen dots on the balloon move away from each other as the balloon is inflated.

It is really the skin of the balloon that is increasing the distance between the dots.
The actual dots are not getting larger.

Another model of the ending universe is that of baking raisin bread.

As the dough bakes it rises and takes the raisins with it. Each raisin sees the other raisin move away. The individual raisins are not expanding themselves

If the Universe is expanding it must have expanded from something that started the inflation.

This start of the inflation is called THE BIG BANG.

After the Big Bang the Universe started to inflate rapidly.

Starting off  like a very hot soup the universe  expanded and cooled down.

Using the Hubble Law and assuming that the rate of expansion is constant then the age of the universe is about 14 billion years.

At the beginning matter as we know it did not exist.

Stars and galaxies formed after about 400 million years.