Your best bet might be to find one or two whose profiles you respond to most, then contact them and let them know you're a newbie. Most are pretty understanding and will be happy to guide you through it, as long as you submit to their screening.

if you're up for a mature wildcat...

I frequent center city every 3 weeks or so. As a matter of fact,  I'll be there later this week

make sure that you meet with a non-clock watcher person, (doesn't mean that you have to over stay) someone that is sweet and give you good vibes. Make sure that you read reviews so you don't have tremendous disappointments. At least with me the apps are very good but you never know... there's some one that is just not happy with you not matter what you do.  
Anyways, the more the lady screen you.. the safer you will be. (thats my opinion).  

I will be in Philly in couple weeks.... for 2 days if you want to meet