and what is it you are looking for exactly? Who do you want to mix with? some of the hip bars currently are in the zone, such as Bio (big favorite of 20something middle class kids, over on Sanchez) and the original bar from the same owner just across the street on the corner (Billini con sanchez). I fyou want to see a typical outdoor "bonche" then head to Duarte Square, also on Billini, where there is usually a huge outdoor party. A more sedate spot with somewhat older people, good rock and roll from the old days and an interesting mix of ex pats and dominicans is "el bar de Maria" over on Duarte, otherwise known as Proud Mary's. The discos, over in the newer part of town, are a nother matter.
There are a bunch of cultural activities as well in the Zone, foreign films, music concerts, exhibitions, etc.
There is also a bunch of young American people here, usually students like yourself, some of whom work with NGOs, some of whom teach English, and some of whom are PEace Corps volunteers, and they tend to know one another and hang out together, but currently I couldnt tell you just where to find them.