Q.Recently Purchased Dracaena Plant
I purchased a dracaena plant and a day later the leaves on top are turning brown. What do I do?
Ditto returning the plant, it shouldn't have turned brown so fast.
Some things to consider in the future: find out what kind of dracaena you have, culture is not the same for all of them.
Carefully analyze soil moisture - dracaenas need to aerate to the point of from slightly moist to barely damp between waterings, depending on the light. Use a wooden dowel of kebob skewer to test the soil all the way down through the pot
Dracaenas do not need, and do not respond well, to a lot of fertilizing. High light, such as near a south window, only need fertilizer 3 or 4 times a year; low light, that under which you can read, but not easily, don't need any fertilizer, just some fresh soil once a year.
Please refer to my YouTube Channel for more tips on watering and light -
http://theficuswrangler.blogspot.com/
I would return the plant for another with assurances this wouldn't happen again. The plant has obviously been stressed by something before you purchased it. Even left if a draft, it would not have turned brown overnight. If you are dead set on keeping it, this article should help: https://www.gardeningknowhow.com/houseplants/dracaena/dracaena-houseplant-care.htm