It actually means seek first the kingdom of God and His ways of doing and being---then all these things will be added unto you.
Well then, what is the kingdom of God and His way of doing things?
Matthew 13:31-32 says,
So we learn a principle here---a very important divine way of how God operates in His kingdom. We first seek His kingdom and do it that way. The way simple: The kingdom of God is equivalent to a seed, and the seed must be sown, and then it grows.
1.Seek first the kingdom of God.
2.The kingdom of God works on the principle of the seed.
3.The seed must be sown to produce a harvest.
When you sow, it's multiplied, and it yields a greater harvest for you to reap---to receive.
Just as a tiny acorn becomes a mighty oak after it's sown, every seed we sow into the kingdom of God has the potential for a great harvest of return, not only for our benefit, but to spread His Gospel to all the world.
As Genesis 12:2 says,