H, welcome to the forum. Glad you joined.
You'll find that we try all kinds of things on here. Some work, some don't. What you are talking about is your own very simple version of a homemade incubator. I'm not sure where you are located. That information could come in handy so I know what units of measurements to use. If you are going to hang around a while (and I hope you do) you might want to modify your profile so your general location is always available.
Your first issue is temperature. You did not mention a fan so you will have a "still air" incubator. Warm air rises so the higher you go the warmer the air unless your incubator does not have a top. Since cool air settles the lowest portion might be cooler than just a bit above. So you want to take the temperature at the same elevation as the center of the egg.
You do not need to be at any exact temperature, there is a safe range. But what you want is the average temperature to be around 99.5 F (37.5 C). You do not want it to get so hot that the embryo dies from heat, so keep it below 103 F. I'd try to stay above 96 F, but it can vary so the average is around 99.5. This is a lot easier in a climate controlled building where the temperature stays the same day and night.
The eggs need to lose some moisture through the porous shell. Not too much but enough. I don't know a good way to measure that in your set-up but that's why that water jar is there.
The eggs need to be turned three or more times a day. If you lay the eggs flat put an "x" on one side and an "o" on the other or maybe make a black mark and a red mark. Whenever you turn them just make sure all have a similar mark on top. Of course there are other ways to do this but to me this is the easiest to explain.
I think that is the basics. A few thousand years ago the Egyptians were hatching thousands of eggs piping in heat and judging how to adjust the heat based on touching the eggs. That craft was handed down in a family so they were experts. You don't have that experience but you can try. You may totally fail or you may hatch some eggs. Good luck!
I have seen YouTube videos of this. It looked like it as in a very hot country however. Let me see if I can go find the link.
