You will not be able to get your tongue pierced at 14. Your parent would have to take you with viable IDs and such.
You need to be 18 to get it done without a parent. Some shops here won't even touch you if your under 16, even with a parent.

I want to get mine done, but I probably won't. I have no fear of piercings on my face or ears, but my tongue worries me with the pain.
It really really takes a lot of care that you really shouldn't have to be burdened with at 14. For a few months you won't be able to eat much other than applesauce and broth, and if it gets infected it won't be fun. I don't recommend you get it at your age, just because your still young and should probably consider it at an older age. Your dentist would not be happy with you or your parents either if you got it done.

I might get my eyebrow sometime soon though. The only facial piercing that looks good on me. Consider getting your nose done or something smaller like that.

Also, getting a tongue piercing may make boys look at you differently, and not in a good way.