Both vocal technique and training are essential for a singer. However, good vocal technique should be the basis. Even if you already have a good voice, a qualified voice teacher will help you develop your voice even further. And a vocal coach will make sure you're ready to perform.
You should go to a singing teacher if you really want to sing professionally or something. Self-learning can also work, but it's less safe. This is just a short list, but you get the idea. One of the most common discussions I always hear about community theater is whether voice lessons are worth it or not.
And my answer to that is ABSOLUTELY YES. I know it's a very bold statement, but I'm not telling you that you have to go find a voice teacher right now and spend hundreds of dollars or you're going to suck at the theater. NO, that's not the case. Some people can manage without them.
However, if you plan to engage in theater professionally, vocal training is definitely necessary. And even if you don't plan to go into theater professionally, the tools and tips you learn in vocal training will benefit you in the long run. The vocal coach can quickly identify weaknesses and problems in a singer's approach, but he also has the teaching expertise and experience that allow him to skillfully guide the student toward development by applying practical solutions. In addition to a voice teacher, an excellent vocal coach who understands where you are coming from and where you are going is essential for any singer trying to have a career.
For example, having prepared specific songs with a vocal coach and having performed exercises that explore tones that far exceed the highest notes of the song will reduce the likelihood of anticipating the high notes and forcing or falling flat on those notes. With proper vocal technique and proper vocal care, the concern of damaging the voice will significantly decrease. Although they may have the same goals for you, a vocal coach is usually a pianist, which means there is no reason for him to give you a full voice lesson. These are deep questions and difficult decisions, but the most important reasons to be with a teacher are to make healthy vocal improvements, solve problems, and maintain a beneficial vocal technique.
A vocal coach is a pianist who usually works almost exclusively with singers and who knows the repertoire.