As a trainer, a question I get asked all the time is, "What protein do I need to be taking?" In most cases, the answer is, "It depends." Generally I'll ask clients these questions: What are your goals? Weight gain, weight loss, or weight maintenance? What is your diet like currently? Specifically, how much protein are you getting? From there, I can determine if a protein supplement makes sense for them.
If your main goal is to build muscle and lose weight, the best thing you can do is get your protein from food sources such as legumes, nuts, tofu, lean meats, and eggs. If you find it hard to get enough protein in each day, I would recommend having one protein shake as a meal replacement and eating the rest of your meals as you normally would. People often have their daily meals plus a protein shake and end up gaining weight because their calorie intake is too high. The only time I would advise adding in the additional calories is if you need/want to gain weight while building muscle.