The best place to store a bike is inside. Shelter will protect it from thieves and the weather. Left outside, a good bike can rust and corrode to dangerous condition in less than a year. This is especially true if you live near the ocean where salt in the air is super corrosive. If your apartment is small, simply install a bike hook and hang your bike from a wheel. These hooks are cheap and they’ll screw into any wood wall or stud in a plaster/sheetrock wall. Be creative: maybe you can hang your bike in a stairwell or a closet; above your bed (cool!) or in the kitchen? You can find a spot if you look a bit.