How can common fitness related injuries be treated at home ? when should medical care be taught ?

Elevate the limb, take ibuprofen
it should be taught from an early age
do you mean when should medical care be sought? if so, it should be sought when there is any excessive swelling, if the color changes more than a normal bruise, if the injury expands outside of the affected area, if the pain gets too bad, and if the pain lingers for a while after the injury

You can literally find this on google of each science career and search up what type of training you need and how many years in school

People who utilizes the progression principle will ensure their exercise program increases in frequency, intensity, time, and type. the changes need to happen gradually in order to ensure they make gains in their fitness program. a person who doesn't utilize the progression principle can still gain health benefits from exercising, but will not continue to improve in cardiovascular fitness.