Advice on my new lifestyle and diet..all opinions welcome?

I went to a nutritionist and I was wondering if what he said is ok. I am a 297 pound individual who hardly got any exercise. After seeing the nutritionist for the last few days I have began to walk 45 minutes a day around a lake. I also have stuck with cereal or oatmeal in the morning. Brown rice and organic beans along with yogurt and pistachios for lunch. And for dinner I have gone with either brown rice and beans or vegetables and some whole wheat bread or maybe a veggy burger. Also including a late night stack of fruit or a weight watchers frozen treat. Overall I am trying to life of a vegetarian because i need a change in life. If you have any opinions please post because I am open to all suggestions. Thank you.