I want to know who my girlfriend goes out with
What happened? Why do you need to know who she goes out with?
Because I developed a paranoid feeling before
I understand it might be anxiety inducing to not always be around your significant other, but they shouldn't be your entire life. That is unhealthy, and you can't always control what they do because that's toxic. If you can't trust them, you need a long talk with them why.
We need long talk because she is being unfaithful
I do not think that it is okay for you to accuse them of being unfaithful as you do not have the evidence to back up that claim and it can just ruin your relationship with your girlfriend if you are constantly jealous about who she goes out with. If you can't trust her or anyone, then I think it is best to go to therapy to see how you can get rid of that issue.