We observed that everything is moving away from everything else (large scale) so the theory is everything was one in the same place. The discovery of the CMB and the fact that everything is “younger” the farther we look out supports this. Since the expansion would have been everywhere there would have been no center of it, or rather every point is the center of it.

A poor analogy would be if you take a picture on you phone and blow it up where did the center of the expansion begin? It wasn’t in the center or a corner, it happened everywhere at once. So imagine that but start with a point.

No, this would mean The Big Bang is an explosion of matter moving outward to fill an empty universe but instead, space itself expands with time everywhere and increases the physical distances between comoving points. In other words, the Big Bang is not an explosion in space, but rather an expansion of space. This would mean the Big Bang did not happen at a particular location but at every location in the universe.

Nope.

Here's a thought experiment that might help explain the issue:

Imagine if you can, an infinite universe that is ALSO infinitely dense. So all of the energy in this universe is crushed down into an infinitely dense point, but this point is also infinite in length in every direction.

Now imagine that ALL of that energy suddenly expands outwards in all directions across all of infinity, becoming significantly less dense in an instant. As the energy decreases in density and temperature it begins to condense into matter. But again, this happens everywhere at the same time across this entire infinite universe. We just happen to be somewhere within all of that.

We don't know if that's what has actually happened but it's one possibility and hopefully gives you an idea of how we can't identify a center or starting point for the big bang. As far as we can tell, the big bang happened everywhere.

Yes, and no. The “point” that everything is expanding away from, wasn’t a mathematical point. It was the whole universe, and is now everywhere. The center of the universe is now right here — no matter where you point a telescope, you’re pointing away from the center.

Not exactly. So the universe is expanding. Think of it as we aren't moving but everything is getting further away. That's an oversimplification, but the big bang was our universe kind of coming into being. We didn't move from a center. We are in a point that is really big now.