How to model 98% ethanol solution concentration graph over time
As Poutnik pointed out, if you boil a 98% ethanol solution (2% H$_2$O), then you will lose a few % of ethanol until you get to ~95.5% ethanol; then the rest of the solution will boil off as if it were a pure compound, for the composition will not change. Well, this is strictly true at the high temperature of boiling at 1 atm pressure. At about 0.1 atm, the azeotrope breaks, and so at that boiling temperature (about 35$^o$C, from a graph in https://wps.prenhall.com/wps/media/objects/3311/3391416/blb1105.html),

there is no azeotrope. I suspect that at lower temperatures than 35$^o$C, there may be no azeotrope. Nevertheless, if you start with a 98% ethanol solution, it won't change much until you have exported off most of the ethanol (like ~75% or so).
I would suggest cutting the concentration to about 50% ethanol, put it in a large beaker (~1 liter), stir with a small magnetic stirring bar at low speed to keep the contents somewhat homogeneous, put in a thermometer and a hydrometer with a range of 0.9 to 1.0 and engage a mild cross current of air across the beaker.
You will be able to determine the concentration of ethanol from a diagram like this:

from  https://www.engineeringtoolbox.com/ethanol-water-mixture-density-d_2162.html using the thermometer and hydrometer. Time is a variable, but is useless for determining any general scientific principle. The conditions of your experiment include air pressure (you can get that), air current (you can describe that - if you don't use any air current, it will take hours or days to do your experiment).
You can read off the volume of solution you have from the graduations on the beaker, and you can then plot the composition of the solution as its volume decreases by evaporation. The measurements are unfortunately not very accurate, but you will be able to make a graph and then spend several pages describing your lab work and potential errors and look up graphs and tables like the ones I have used. A likely error will be that the temperature will not be constant, the liquid level will drop so that the air current will have different strengths.
And as MaxW pointed out, the modeling may not be very &quot;realistic&quot;. But I think people will be impressed with your use of scientific equipment and your analysis (which will be of the highest caliber, I'm sure).
While 50% ethanol is a lot less flammable than 98%, it still is a fire hazard, especially in quantities as big as a liter. Not only the liquid, but also the vapor is hazardous, so make sure that there are no flames or sparking devices within about 20 feet of your experiment. And have good overall ventilation: ethanol vapor can put you to sleep or make you dizzy. For extra security, you should plan to have a fire extinguisher handy (and know how to use it).