what should i have told her?

Hi guys,

I was in my friend's place on last Friday, and i was leaving his place in the next day's morning. On the elevator, i saw two girls. They were going their floor(5th floor), from the building's fitness room. They said hi, and i said hello. Therefore, i was forgot to press on any floor, she said which floor are you going to , i said 5, oh no 1, 5 i said , then the pretty girl said if you would like to come for brunch, then i said if you invite so. I don't know what i said that, it was sounds like an invite already. Then i shut up, they were looking at me and i did, and some other people came in elevator, they were leaving she said have a good day, and i said have a good day.
Then i was thinking like what should i have said to them... Probably i should have said, i am pretty busy today, but why don't i buy a coffee or breakfast tomorrow? Or maybe i should have said, aren't you going too fast? Why don't we go to launch tomorrow? or maybe, You ladies are too friendly, but i don't go to launch in strangers' house, but there is no problem with going outside for launch tomorrow, would you like to give your phone num? I don't know god dam me i couldn't say any of them when i was fall in love with her beauty... Tell me your opinion? What would work best?

You were probably too nervous for anything to come out anyway sorry to say...

Her asking you was basically an invitation so you could've just said "OK" and just introduced yourself after that.

But it happens sometimes so don't beat yourself up about it. You might see them again.