A singing lesson can make you feel more confident about singing in front of others.
Some people know they have a good voice and seem totally confident singing karaoke at the staff party whilst others mumble the "happy birthday to you" song under their breaths hoping no-one can hear them sing. Singing is a learnt skill - sure some people are born with more singing talent and tonal recognition than others, just as some people are naturally better at mathematics than others. Like anything though you can always improve what you have through learning.
Getting a professional to give you a singing lesson will improve your confidence and make you feel better about your voice. They will be able to teach you techniques and scales to practise to improve your vocal range and tonal perception.