What do we do if SETI is successful?

For a somber, deeply intellectual view of what could happen, I can't recommend enough Stanislaw Lem's His Master's Voice: https://en.wikipedia.org/wiki/His_Master%27s_Voice_%28novel%...

"Given that our civilization is unable to assimilate well even those concepts that originate in human heads when they appear outside its main current, although the creators of those concepts are, after all, children of the same age—how could we have assumed that we would be capable of understanding a civilization totally unlike ours, if it addressed us across the cosmic gulf?"

Me and my dog cannot talk.

I understand my dog and he understands me.

If they experience death then we have massive common ground already.

Humans and dogs have evolved together to be cooperative…

would you feel common ground with a predatory fish? Or a plant? An insect colony?

We all share many similar biological imperatives And these contrived examples because we all evolved on the same planet. Even the worst case scenario of the Dark Forest has many anthropomorphic priors within.

Imagine an intelligent shade of blue. Thank you, Douglas Adams. I suspect we have no idea WTF is out there and I'm not a carbon chauvinist like Carl Sagan was. But I wish I would have lived long enough to find out and I suspect that won't be the case.