I haven't been to one myself, but I've heard good things about them.

a few thoughts about non X rated venues

Here are a few non - X rated places you might check out-

State Lounge    

Dave's and Busters (in the Providence Mall) Twenty something/thirties But cruising the Mall can be interesting if you are people watching. And Dave and Busters you can play games that may lead to conversations with the ladies.

E & O on Federal Hill (Bar)  

Mardis Gras Multi club -in Cranston  
If you have a car, and it's just down the road a bit from me

Old school and new school  it's a win no matter what your tastes  

I can give you bar recommendations but not sure on meeting dates. If you are staying downtown, in addition to what others said, you can try Station Brewery or Trinity Brewhouse, Bar Louis, or Temple in the basement of the nice hotel just north of the mall. Temple is pretty cool. They make good drinks. I was there over the winter but heard a rumor it might have closed. Call first on that one. Around this area you'll likely meet more tourists/travelers staying at the walking distance hotels.

Driving? The Hot Club (not a strip club) is sort of a mixer from all ages/walks of life. They'll have good outdoor seating. Weather supposed to be very good tomorrow/Friday. Federal
hill if you want high end Italian. I tend toward the Irish bars like Fat Bellys, McBrides or Whiskey Republic or Murphy's Law in Pawtucket ("the bucket") or bars like Dorrance or Avery.  

Providence has too many phenomenal restaurants to even attempt to name.

Have fun!