How big is the universe really?

Can we measure the universe? Not just the "observable" universe but the universe entirely, or is it infinite?

Enormous space scattered with stars, dust, suns, particles, planets and much more than we can even imagine.

The "observable" universe.

The observable universe is finite. It extends 46 billion light years in every direction from us. (Our universe is 13.8 billion years old, the observable universe reaches further since the universe is expanding)

Once we are past the observable universe, we are into unknown territory. Probably infinite, going on forever but can it really be infinite? Is there such thing as infinite, never ending? Can you wrap your head around that? It's hard for me to do so.

Never ending space

Can we imagine for a second that we have a very fast space ship and unlimited resources to travel non stop at millions of miles per hour, better yet we can teleport anywhere in space and we choose a few million miles away every time. Exploring and pushing the limits on how far we have traveled before. Will we hit a wall eventually? Or "fall out of the sky"? What happens once we travel billions and billions of miles? Is the universe really infinite?