Hallo

I see that as your name states you are indeed have a lot of "self doubt".
And I got to say that it is normal, because everybody have self doubts about themselves.
But the thing that gives you the assurance you are working out right is basically experience which you lack (as you say).

I got to be straightforward here and say: if you do not "jump in" and try things you will never abolish these self doubts.
If she comes out and joins you for a 2nd date that means that...SHES INTERESTED.
and as long as she is interested, you have a green light to push things forward.

Believe it or not, they always want us guys to push forward, they want us to advance and carry from 1st to 2nd and so on...
I bet you know this by yourself.

I highly recommend reading Deangelo's book
because it helped me a lot when I was starting out dating with girls, and when i used this information sub consciously I became better & better as time passed on.

Practice makes perfect, especially if you go about it over & over again. If you want to get an extra edge
try his book for assistance...

Good luck!