system
Given the following post, respond as if you're commenting on Reddit:
human
[The Culture]I am a member of a species capable of interstellar travel... for like three hundred years. Can I immigrate as an individual to join the Culture?

My civilization is pretty proud of the fact that we went from our first launches to our moon to exploring the local corner of our galaxy in three hundred years!  We even started our first colonies on planets in nearby systems fifty years ago!  We are a peaceful species but far, far, far less advanced than pretty much every other species in our neighborhood.  Our cultural values focus heavily on respect for the self determination of others, cooperation and non-violent solutions to our problems.    
    
We recently learned about the Culture from one of our neighbors and WOW!    
    
From what I understand, our civilization is seen as far too primitive to join the Culture.  My species has not discovered biological immortality and we have not extended our lifespans dramatically compared to how long we lived before we discovered space flight.  I won't live long enough for my civilization to ever join the Culture.  If me and my close family can make it to a Culture ship or habitat in our own, would they allow us to immigrate?  If anyone else has done this, what is the process like?  How do we make a good impression?  We are a bipedal mammalian-like species, so we even sort of look like them!  Kind of!  Except we are er... twelve feet tall.  Our homeworld has lower gravity than many other typical humanoid species.
gpt
We have a couple of examples of people from cultures about that advanced becoming Culture citizens, insofar as such a concept exists.

But they aren't exactly *recruiting*; you'd probably need to ...find one of their habitats or ships, hang out there for a while, mix with the people. They're pretty informal about these things, if you end up with a few Culture friends (even if it's just the ship's AI avatar) you should be fine.