I'm thinking about becoming a vegetarian! 
You should , a fact is that veganism is  the practice of abstaining from animal products 
Is it healthy to be a vegetarian? 
It is said to be healthier .  A follower on this diet is also called a vegan 
If I become a vegan, can I still eat dairy foods like eggs and cheese?
You can't eat any animal products, not only meat but also eggs and dair products you can't consume those either
Oh, okay. I'm not sure I can do that! What are some other reasons people become vegetarians?
Not much information on that but i did find that the german's do not recommend vegan diets for children , or women during pregnancy . 
Oh really? Why is that?
Not much information but i would assume since a child needs all the nutrients from a young age