Many young adults live alone. Most of them live in rented apartments. If you are single and looking for an apartment to rent without a partner or roommate, then you need to take your own safety into consideration. It's important to know that the place you rent is secure, and that you will be safe there when nobody else is around. Specifically, make sure you check for these features before renting a place.
A Well-Lit Entryway
It's scary to think about, but you would not be the first person who was kidnapped or otherwise harmed when walking to their front door at night. You could also slip and fall on some ice in the winter, and with nobody inside expecting you, it's possible that you could lay there for hours before help arrived. Make sure the apartment you rent has a will-lit entryway, as this will both deter criminals and keep you from tripping or slipping on obstructions you might not see in the dark.
It's always a good idea to have a deadbolt on your door -- but especially so when you live alone and don't have anyone there to help defend against an intruder. In addition to checking that the apartment has a deadbolt, make sure that the landlord will change the locks before you move in or allow you to do so yourself. This way, you can be confident that no previous tenants -- or their friends -- have copies of the key and can access the apartment.
Consider visiting the apartment at different times of day, and get an idea of what the people in the neighborhood are like. Are the neighbors willing to strike up a conversation? Are there any "shady" characters that don't quite feel trustworthy? When you live alone, there may be times you need to call on your neighbors for help, so it is important that they are friendly people who you feel that you can trust.
One way in which intruders often enter homes is through windows. They may shimmy something under a partially open hung window and slide the window up until they can fit through it. When you live alone, you really don't want to come home to an intruder in your apartment! So, check to be sure the windows lock closed. And then remember to always lock them shut when you leave.