I was reading online that its bad to give a kitten a wet food only diet because they can get tartar faster and that they eventually lose their teeth. It said you r suppose to feed dry as well to help with this. Is it true?
You are to be commended for doing some research about nutrition and cats.
Whether they get tartar is dependent on several factors, only one of which is food, especially when very young, and genetics.
For general information about choosing the right food, here is one article. And one about whether http://www.thecatsite.com/a/does-dry-food-actually-clean-your-cats-teethfood cleans cats teeth.
Personally unless you KNOW your cat is prone to dental problems and/or already see them, I would stick with wet food. If your cat is willing, you can brush their teeth. Some members really like dental products. Here are reviews of some of them.