I lived near the Francisco stop on the Brown line and loved it. I moved out of state about 4-years ago. You can take a trail through a few parks all the way north of Northwestern in Evanston if you want. You can also easily get to the path along Lake Michigan just north of Wrigley. There's a Fleet Feet store between where I lived and the lake (Old Town). They had regular group runs and could help you find more routes & people to run with.
I was about your age when I moved and there were a few areas good for being single nearby - Lincoln Square is cool, but not for me, I preferred Andersonville. Francicso was more of a family area - which made it safe and much cheaper.
One stop further away from the lake was Kedzie. There was a good pizza place that wasn't the typical chicago-style. Golden Crust I think. Great beer selection from what I remember.