Okay.
So we’ve got an entirely flat surface that also happens to be the exact same length as the earth’s surface.
If you had one continuous piece of string that went from one end of that flat surface to the other, and on one end there was attached a bell… would you be able to ring the bell by pulling on the other end of string?
No one has really answered you so here you go. Yes you would be able to. It’s not instant though because information and energy cannot break the speed limit of the universe (speed of light). So essentially you’d pull the string and a few seconds later the bell would ring. Extend the string to the sun and it would take 8ish minutes for the bell to ring.
Speed of light is a lower limit but it would actually be the speed of sound in the material of the string that matters, so likely much slower than C
The speed of light is so much faster than the speed of sound, and that’s why sometimes you think someone is bright at first until you hear them talk.
:-)