Nailed it with the presentism, close on eternalism.
Eternalism as “The idea that all moments exist simultaneously” is correct, but “This means that the past, present, and future all occupy the same point of space-time, and are all occurring at once,” is incorrect. The past, present, and future all occupy all points in space-time.
I think I know what you mean though. To exist outside of time is to hardly exist at all from our view. There is no movement, no thought. No life nor death. One could not observe the space-time continuum from outside it because one could not do anything at all outside of it. If you were to exist outside of time, it would be as if you occupied a single instant. A single, unmoving point, entirely frozen. And that’s a bit how space-time works. It’s static, and it doesn’t change, but unlike something outside of time, space-time contains time. Space-time is the flow of time even though it doesn’t flow itself. I suppose it’s like how rivers don’t actually flow themselves, but rather it’s the water that’s in them that flows.
Hopefully that makes sense. Thanks for asking for clarification.
Awaiting your response,