chances are you will always have a fear of the unknown,
best way to get over this is gain experience doing it,
chiefs-guide-to-outer-game-vt75887.html
you can use chiefs compliance ladder, in the above link, or google vin dicarlo escalation ladder, or find a billion other escalation ladders, just pick a strategy and stick with it, execute the plan until you don't need one and feel comfortable expressing yourself
I suggest something as simple as either, getting close to her yourself, or telling her to come close to you, put your arm around her, if all good so far, go for a kiss,
not trying anything gets you the same results as trying and failing