First point.
The health issues, if there are any are quite different between WiFi and mobiles. This is due to two factors. Mobiles use a different wavelength to WiFi, so what could apply to one would not apply to the other. Second there is a thing called the inverse square law which says that if you double the distance you quarter the intensity, so if you have a mobile jammed to your ear the intensity of exposure at the skull will be large compared to it being even a couple of feet away.
Second point.
The amount of energy in WiFi is trivial. If it were not then the electricity bills of everyone with a router would be immense. and you do not jam a router to your ear.
Third point.
The official government precautionary advice is that young children should not use mobiles for any extended periods, not because of evidence of harm, but it is clear that an adult skull will block most mobile radiation a child's skull will not, and a child's brain still growing. So why take the risk?
Fourth Point
WiFi everywhere; there are eight networks reachable by my computer now. School wiFi neither here nor there.
The statement that male sperm can be affected by radio waves is, I have to say, in general, nonsense. Tight underpants would have a bigger effect.
Yours in loose fitting boxer shorts.