Breed Dog

What is a good small breed dog for my circumstances?

I live in a duplex which has a big yard but it is not fenced in. I would need a small breed that would be mostly inside but would have room for plenty of walks and outside time.
Also, I have a 7 year old and a 15 month old so the dog could not be nippy or aggressive at all.
Do you have any suggestions for a good breed for myself and my family?

i would not get a toy breed with a 15 month old. Toddlers like to pull at things and dogs can snap at them quickly. Sometimes it works with toddlers and small dogs but most of the time it doesn't. Something a little bigger. Maybe a beagle. My grandson had a beagle when he was a toddler just a little older and they did well together.