I assume that may have something to do with it, though, I am unable to find anything on fixing it.
Yes, your mistake is simple and related to that warning message!
pay = rate * hours;
overTime = rate * 1.5;
The place of the above statements is incorrect. If you need to calculate something, you need to get inputs of that calculation first. But you do the calculation first and then get input! And compiler warns you because of that since you did not initialize rate and hours variables.