How did you do and start conversation to a girl on phone for the first time after you got her number?
Depending upon country and circumstances you might say something like; “Hello”, my name is [Austin Powers] or whatever you real name is…
Then you remind them that you were the guy she met that was a ‘mighty webmaster’ (very unlikely in your case as that’s me, and all the girls fall for that line without fail) or whatever any pay her a compliment; saying how wonderful it is to talk again, etc.
To be honest it depends upon why she gave you the number for in the first place, I assume she is a ‘good girl’ and not one of those naughty types?
In which case are you asking in the context of developing a future friendship or meeting up for a date?
Without telling us more about the back-story it’s a little hard to say exactly as assuming; unless she was fobbing you off - or was the naughty type - the odds are she liked something about you anyway. So it should come natural and you should ask her if she has time to talk first, or mention a little about your last meeting, etc.
Better tips but I think it has to be a little but flirty. Am I right? Assume its about friendship. If a girl gives you number for just friendship then I think I wont go with that much etquettes.
It is said that friendship is first step of love, so sooner or later you are definitely going to start flirt so better start from the first time because it is sure that you are interested in that girl.
thanks