How to get confidence in yourself so you dont feel the need to ' justify ' yourself to people?

First of all i dont know what aloof means, more confidence you need more confidence theres one solution that seemed to help alot of people i know its call center work, it builds up your communication with other people teaches you how to talk to people make them like you. Ive seen people go into call center work that could barely talk to people bu after like 1 month on the job they were confident enough to talk to anyone.