Recently saw a mod where you parachute into a starting location, like a Rambo-type character. That got me thinking: is there a mod that presents an objective to the game, where we come landing in from a helicopter or plane, and have to survive, but also figure out how to put an end to the virus, with a backstory involved? Something like needing to go to multiple locations to find different pieces of paper from scientists with information on a cure or who was behind the outbreak, and then travelling from place to place, interacting with the people at a head quarters, or something?

Closest mod I know to an 'objective'. Basically there are four radio weather stations on the map and eventually the emergency broadcast will die off, in order to fix it you need to find the locations and information on how to repair them. I believe it repeats too, so it's not just a one time thing if I am correct.
https://steamcommunity.com/sharedfiles/filedetails/?id=2398274461&searchtext=broadcast

This might be what your looking for
https://steamcommunity.com/sharedfiles/filedetails/?id=2907683021&searchtext=insurgent

Thanks for both proposal guys! Me and my friends are deadly waiting for a mod with a story. We're not a lot into "surviving" just for survive.

Yes. Thank you for the suggestions. The second one looks more in line with what I had in mind. Very cool!