A sound building or structure will keep out most of the street noise. Make sure your bedroom is either facing away from the main street (if there is one) or is relatively sound-proof. Also, visit the space at different times of the day. Check out the neighborhood to see what's around. Stores will exude less noise than bars or baseball fields. Also listen for noise from other apartments or houses.
It's a very different living environment to be next door to a retired couple than a young family. You may prefer to be a younger neighborhood or building or maybe you like it quiet? This is critical to your happiness and that of your neighbor, too.
So, after you've asked and pondered all of these questions, the final, most important one of all is, can you imagine yourself living here? Does it feel good?
If this last question is yes and yes, some of your other answers may not matter. Listen to yourself. Enjoy the experience, after all, you only move into your first place once.
