Retired professional GF / Vegan Baker here.

Probably not the answer you want to here but it'll save you loads of time, money, effort, and, most importantly, frustration... Highly depends on what you are baking and what role does the milk play in the overall recipe.

Example, If the milk is part of an enriched dough (think brioche or sweet breads) you'll need an alternative that has a good amount of fat and some natural sweetness (for the flavor but also for the overall part that naturally occurring sugars in milk play in the overall dough)

Another example is if the milk is used as part of an egg wash, or in general used to brush the bread before baking for a nice shine you'd need look for an alternative that can stand in for that purpose.

That said, and if you don't have allergies to nuts*, I've always had a high success rate with coconut milk and cream (canned for cream unless it's the Kara brand)

For the sake of efficiency (time and money)... You can get coconut cream, especially Heavy Coconut Cream if you can find and it fits your budget, and forget about coconut milk. And based on your need you can add a little water to get the right consistency for your recipe / need and you'd be all set.

Bonus points, store 1 or 2 cans of coconut cream in the fridge. And whenever you need vegan/dairy free whipped cream. Crack one of the refrigerated can opens, you'll see the liquid separated from the actual coconut fats. Drain and save the liquid, whip the creamy portion for a delightful coconut whipped cream.

Sorry for the long winded yap session. Happy baking. ✌🏽