Is toddler milk something you'd use if you stopped BFing before 12 months? I've got no idea about any of this!

I'd love to BF Cooper until at least 12 months but I'm probably going to have to go back to work. So I guess I'll need to start weaning him around 9 months? How many BF does a baby that age need per day?

So basically he'll need something until 12 months of age (as I know you can't give cow's milk to babies under 12 months). Is this when you use toddler milk? Or do you have to use formula?

There's a lot to learn for me!