I am sure you do because this would make you more valuable as a painter. If I were hiring a painter I would want to make sure that they had proper insurance so that I would not be held responsible for any injury they might obtain on the job.
The companies I work with have a minimum earned premium of 25%. So technically you can buy it by the job but it will cost you a lot more than if you kept the policy for the year.
I think most states will not allow a minor to enter into a contract until they are eighteen, but check with an insurance agent in your area.
Really most states will allow persons of any age to...
There are many many different jobs in the insurance field. Sales, marketing, management, claims, information technology and computer jobs, actuaries, secretaries, data entry, etc.