I have always had German Shepherds, from when my youngest was four, but we had them in the family, so I was experienced. I fostered, as well. He was two when I got him from "German Shepherd Rescue".
That was a good age to mix the dog in with, they have lovely memories of my first male dog.
They are part of our leisure activities of walking and camping.
My present one, was my first puppy (my others were rescue). I had sleepless nights for a month and even with an insulated walk in kennel and run, I live with a level if dirt.
I mind my nieces little boy, from birth and the dog has to be put out at times. I have to clean the whole kitchen before he comes, the cupboards, skirting boards, freezer door etc.
We joke that my dog thinks she a Lab or Spaniel, she loves water/mud/swamps. Comes in all excited and everywhere is splashed.
I have time to clean, my now older teens help, but we live with an accepted level of dog hair and dirt.
It's not a level that I would want with a baby/toddler tbh.
I grew up with a King Charles, lovely little dog, didn't like dirt, loved getting bathed and dried with a hair dryer.
Invest in a kennel and run, first, £400+, if you do go ahead, there will be times when you need this, which such young children.