It is confusing isn't it? Again and again someone demonstrates gravity with a sheet and a ball, and again and again there is someone looking for or talking about the 'graviton'.
Another one: The presenter starts off with an illustration of space and time being -the same thing: "space-time". But then goes on to explain space only, or time only, or both but each in their own silo.
My approach to understanding this has been to watch every documentary I can, distill the common, repeated 'truths' and extrapolate a mental image from that. I think space and time are -literally- the same thing (the perpetual expansion of space -is- the passage of time), gravity is -not- a force, there was no big bang, nor was there inflation.
Ok, the last bit is somewhat radical so I'll explain a bit. The universe (space) is always expanding, slower when there is nearby matter with mass, faster when there is not. When galaxies are so far away from each other space expands so rapidly there is a "breach", covering a huge astronomical area, in which energy/matter rushes in uniformly, slowing down the expansion.
I have no math skills and might be completely wrong, but it feels right and I'll probably hold on to this mental model until/unless there is some clear irrefutable proof otherwise. Really, I don't see that happening because (lol) no one is every going to investigate the scenario I just described.