I need a diet plan

I am an obese person and I have to admit that it bothers me a lot. I crave a better body but I cannot seem to get it. My friends told me that working out will help. Therefore, I attend a gym twice a week. However, what I do train are my big muscle groups. One guy at the gym told me that I will not trim any fat doing the exercises I do. He told me that I will gain strength and build muscle mass but I will not lose any fat. He added that the muscles I will develop will be covered with fat anyway so they will not be seen. Those words were quite harsh but I believe him. What I have to focus on are other types of exercises, I guess. Something like running or cycling would be more suitable for me. However, training alone will not make me a healthier and better built man. The most important thing right now is a diet plan which I have to get as soon as possible. Without a diet plan ... without a diet in general I will not succeed. I will still be unhealthy and still have all the fat. I need to eat well and work out to get rid of the obesity and together with it all my nightmares. Do you have any idea where can I get a good diet plan at? I would really need one. I want to change my miserable life.