I don’t think I’m a dumb person. There’s some complex stuff I can understand, but whenever this comes up, I just can’t wrap my head around the shape of the universe and why is it exactly that the universe started somewhere and now I can look far enough in any direction and see not only that place, but also in the time it happened. Mind boggling.

It didn't start somewhere. The Big Bang happened at all points in space. It happened "everywhere".

We’re inside an inflating balloon and the space inside is a giant gobstopper where each layer is spherical movie projector screen we can watch a movie on of different moments in time.

If we’re not literally on the edge of the balloon is someone else looking back in time at us?

That's true except also every other point in space is at the center of its own balloon. The balloon has no edge, the movies just become too dark to see past a certain distance.

Too dark and yet also too bright: the fun combination of a plasma so hot and bright it's opaque being redshifted so hard it's the darkest blackest void anyone has seen.