y advice would to be that once you get their phone number, don't continue the long conversations via text.
They gave you their number so you can move the relationship to an in-person meeting, not to continue your conversation... if they weren't pretty certain they wanted to meet you then they wouldn't have given you their number in the first place.
When you get that phone number I'd suggest your 2nd or 3rd text message be something like "So we've been talking for a bit and you seem pretty cool.. Would you like to get coffee this weekend?