Why didn't the universe always exist? Because since God is supposed to be outside of time and is supposed to have always existed, then how could God have used a point in time to start creation? Any thoughts on this?
If God is beyond time, then everything that has happened, is happening, and will happen are all concurrent. But that doesn't mean that a beginning doesn't exist.
So, yes, the universe always existed. And will always exist. You have always existed, I have always existed, and we always will, according to the premise. Our beginning, middle, and end, have always existed as well.
Given this, you have asked "how could God have used a point in time to start creation?"
Because one of the properties of "creation" is that it has a "beginning". "Beginning" is just a label. It's almost like a name.
"Creation" is just another character in the story that is being authored. Just like any character in any story, the author can construct them however they like. The timeline within the story doesn't match the timeline outside the story. The author can be beyond time, and one of the elements of the story can be temporal.
So it's both. Creation has a beginning, and it has always existed.