In dreams, milk usually symbolizes the more basic, elemental teachings of the gospel / discipleship. We give milk to babes and reserve meat for those that are a little older or further along in their ability to chew and digest.

I fed you with milk, not solid food, for you were not yet strong enough [to be ready for it]; but even yet you are not strong enough [to be ready for it],

1 Corinthians 3:2 AMPC

However, milk can also be a representation of flowing abundance as we see in the promise God spoke to the children of Israel:

And I have come down to deliver them out of the hand and power of the Egyptians and to bring them up out of that land to a land good and large, a land flowing with milk and honey [a land of plenty]

Exodus 3:8 AMPC

As usual, consider the overall context of the dream to determine how the symbol is being used in the dream and above all, ask the Holy Spirit for revelation.