Google login/signup auth

I’m using bubble’s Google OAuth to login/signup users to my app.
But they share the same action (login and signup) at the same workflow wich is not flexible at all.
I see a bunch of tutorials showing how to do it but it seems stupid or incomplete. How do i know if my account exists already when they share the same actions in order for me to do changes to that user in a dynamic way? what am i missing here?

What I’ve done…

when a user signs up/in with Google I have the following workflow.

First I sign the user up/in. Then in step 2, I make changes to a thing with a conditional that the make changes to a thing only runs if the first name is empty.

If the user has signed up already and is just logging in, their first name won’t be empty so it won’t create changes to a thing.

I also use the info from step 2 to populate a profile page that the user can edit.

Here’s a screenshot of how I do it: