stinky water is part of cycling if you do not have any biological filteration established prior like setting up a tank with dry base rock only.
You will need some test kits to determine what stage of cycling you are in, I would recommend Ammonia, Nitrite, and Nitrate test kit.
You will see an ammonia spike first followed by Nitrite spike and finally nitrate. Nitrates will read positive when you have nitrites
so wait until you read 0 or close to 0 reading of nitrite before testing for nitrate.
If you have started with base dead rock, I would take out the dead fish since base dead rock will contain dead materials in it to start the cycle anyway, you can keep the dead fish in there but it will prolong your cycle.
Since you have no livestock in that tank, there is no need to do water change until you read low to no nitrites. Let me know or call me if you have any other questions. The whole process can take up to a month depending on how much dead materials are in the tank.
Cagri