You just have to work up the courage to say Hi! Don't ask for permission like:‘’Excuse me, can I ask you…’’. It would makes you only more nervous and isn’t necessary. Just skip the apologies and start with your opening sentence.
It's always a good start to ask a question, that would cause a question to you. Like"How’s your say been?". If she is interested in talking with you, then she would ask you the same and you'll have the opportunity to tell her something about yourself.
That way you can see, if she is open to have a conversation with you or not. If she answers short without asking something about you, them you should let her alone. #guycode
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