The big bang happened everywhere. We can only see as far into the past as the radiation from that event will let us.

Pretend you’re at a fixed point inside a very smoky half filled balloon. Then somebody starts filling the balloon with clear air and now you can start seeing stuff as the smoke disappates. But you can never really see what the inside of the balloon was like before or during the smoky period.

And the balloon just keeps expanding at an accelerating rate.

And also the balloon may be infinite / may have always been infinite / but you don’t know because you can’t see further back than the smoky period. You’ve never seen an edge, the smoke was the edge, was the smoke infinite? And the only thing you have to figure it out is math that you know is wrong.

Basically there may not be an edge. The big bang happened and we can’t see an edge in any direction. Just more places that experienced the big bang just like we did.