What to say at the end of first date?

Scenario 1. Good date but I don't think I am interested. End the date feeling a bit bad about it so I say "it was really lovely to meet you. It would be nice to know a bit more about you. Shall I give you my n so maybe we can arrange another coffee?" While my mind is saying to me What the hello why are you giving him your number you idiot?

Scenario 2. Good date and I would like to meet this man again. Not 100 x cent sure but yes I would like to know more about him. But I am a bit unsure about how to end the date so I say "it was really lovely to meet you. It would be nice to know more about you if you would like it. Maybe we can swap numbers on the app and arrange another coffee?" While by mind is saying to me Why are you doing his job on his behalf you idiot? Guy obviously says "yes that would be very nice" and clearly I have no idea if that was meant or it was me putting him in the position of having to say so.

So...I think I need to have some urgent prepared script in my head to learn by heart and recite. That includes silence of course. 

In both scenarios I just felt bad not saying anything...that's probably the underlying issue.

Thanks for advice. Will be very gratefully appreciated x