Might I recommend some visual aid, indeed there are more questions than answers as you come to realize that the more you know the more you don’t know.
Go to youtube and ‘favorite’ (that way searches pop up automatically) Kosmo, SEA, (especially) and Astrum for starters - there are many others that are excellent also too numerous to mention. If you don’t have a big screen TV you’re gonna want one!
Also do a search for the JWST (James Webb Space Telescope) and see some of the new findings, staggering discoveries that are turning astronomy and astrophysics on their heads.
The JWT has for sure introduced some new ideas into the question. I don’t believe we can have any idea how large the universe is, we can only deduce how far we can see objects in it away from us and that currently happens to be about 13.8.billion light years. Before James Webb it was about 13.5. The universe didn’t grow because of the Webb telescope but we can see a little farther out into it.
The JWT can also see a longer wave of light than other telescopes so that light that would have dropped off our ability to see is now visible to JST. To double the distance that we can see, that is add one directions visibility to the opposite directions visibility would give us 27 billion plus light years. We know from what we can see however at 13.8 billion light years that it is larger since we can see formed galaxy’s and stars at that distance. If the big bang theory is correct we should see large gas clouds and no individual stars before we get to the edge of what we are calling the universe.