Testing worldwide has found very few children infected by COVID-19 This may be because children tend not to exhibit symptoms so they are not being tested. Except young people under 19, the virus seems to be spread pretty evenly through the population. In children under 9 the percentage of infection is just under 1% and for the age group 10-19 it is just over 1%
The trouble with all COVID-19 statistics is that only people with symptoms are being tested. There is no way to know what percentage of the population is infected without taking a statistical sample of the entire population.
Older people are at high risk of complications. So is anyone with a compromised immune system. Diabetics of any age should be particularly careful
Here is an article on the current situation as of March 15, 2020. There is a lot of information about COVID-19 on the internet. Some are good and some are complete lies. Check your sources.
I tend to trust foreign data more than the Federal Government. The CDC information is reliable but is not that transparent. The Hawaii Department of Health (HDOH) has stated that COVID-19 tests require a prescription, My doctor has told me he has a terrible time trying to get COVID-19 tests performed.