You need to look for a dog that doesn’t require a lot of space and time running around. Some breeds need more than others. If you live alone, you also want to look for a breed that can handle being alone while you are gone. You’ll need to consider potty training, obedience training, feeding, vet bills, and what your apartment’s policy is on dogs. Which way you potty train may depend on the dog. Some things are better suited for certain breeds, so once you find the breed you want, you can plan more from there. You could also look into adopting an older dog that is already trained.