You need to start somewhere. Confidence will come from experience. Also nofap site could get you started.
If shes talking to you then you are good looking enough. Man don't have to be beautiful, man have to be smart. My married friend told me - look weight or age dont mean anything if you feel good with the person and have something to talk about.
Maybe give her a compliment and ask some questions before asking out to prepare her a little. That way she will understand what you see in her and see that you're interested.
Doubt kills more dreams than failure ever will