Should I get a guard dog?

Hi!

My husband has recently started traveling for business quite often which leaves with me with my one year old son alone. He’s gone about 7 days a month at this point. I feel like it would be nice to have a guard dog to keep us safe when he’s not around. We live in a pretty safe area but you never know. My husband only wants a puppy and refuses get an adult dog. Is it crazy to get a puppy with a one year old?