I'm in a similar situation as you.. except I'll have two to train on my own. My filly is going to be 2 in April and the gelding will be 3 in March but I probably have one up on you as they've both been shown in halter classes so they at least have ground manners already.
Does your baby have any training at all or are you starting from the very beginning? If the baby is at least halter trained then you have a good foundation at least.
I'm no expert and I'm sure you'll get better replies from the experts on here but I would suggest that you read... read... read. As much as you can about how to start a baby. There's PLENTY of stuff online to learn the steps and how to do them safely.