There is a star buck on Main (Conner b/w chicago and Main), 1 to 2 minutes walk to the El-stop. Right there is also the Northwestern intercampus shuttle bus stop, so when you have to Wildcard you can get on the bus for free (I have been doing that for the last week, since I'm working in the chem department right now). Jewel - Oscos (grocery store) and Whole foods (organic food store) are right down the street, a block from Main street. There is a mexican restaurant on Main, next to the metra station, subway at the corner of main and chicago, greek restaurant on Chicago, Thai restaurant about a week toward Northwestern direction, as well as an Ethiopian restaurant. There are many more in Davis street (downtown Evanston) only 15 minutes walk (about 3 blocks or 2 El-stops). The area is very safe, I have walked around at mid night and have no problem at all. However, you still need to be careful since you are still in one of the biggest cities in America. FYI, I live close to Main and Chicago. Main is the pretty long road so I'm not sure about other parts of Main. However, the area between main and Dempster are very good to live according to many graduate students walking in my lab.
It's also very easy to get to Chicago from Main. You can hop in the El-Train at Main, switch to Red line at Howard and get to downtown with only 2 dollars. If you like ethnic food, you can go to Argyle (tons of Vietnamese and Chinese foods) or go to Chinatown which is much further away on the south side of Chicago. They are both red line El-train stops.
Good luck with apt hunting