Q.Coconut Palm
I was shipped a coconut palm seed that had two small leaves on it. As stated on instructions, I put it in a shallow water container, where it lives today. But now it is 6′ tall. My question is how do I plant it? It has to stay indoors. What soil does it need, how will I know when it needs water, etc. ? I basically need to know how to keep it alive.

Certified GKH Gardening Expert
Go ahead and plant it in soil that is 2/3 potting soil and 1/3 sand or vermiculite. It probably should have been moved to soil some time ago, but it sounds like teh company did not tell you that, so you wouldnot have known. I will warn you that at this point in time, if it has grown in water until it is 6 feet tall, it may not take well to being planted in soil. Some plants just get use to what they grow in and then don't like to move. But, you can give it a try and see if it works. If you seeit not taking well, you can always move it back to water. But, to help it try to be as successful a move as possible, be sure to water very frequently.
Here is an article on growing coconuts and their care: https://www.gardeningknowhow.com/edible/fruits/coconut/growing-coconut-palm-trees.htm