First Aid is an essential training which can be useful for all ages. Knowing how to attend somebody when they have suffered a wound or complication can be a life saving skill.
First Aid courses do not teach you how to save life or perform delicate operations, but how to attend somebody in distress and make them stay alive until qualified rescue teams arrive.
Knowing about first aid techniques will not necessarily land you a job, but can help, along with a certificate to obtain one. For example, in the UAE, all sports coaches need to have both a certification and a valid first aid certificate in order to work legally.