Melanie, you are just to young to go into a coffee shop. Even the Dutch know their limits and so should you.
If you are 15 your brain is still in development. There are some good books around with a fair view on this topic and not written by people who are against the use of cannabis in general. Just read more about it so you can make a much more informed decision and wait a couple of years till your brain is developed. (Which got nothing to do with growing up or being sensible or clever , so don't take this the wrong way, I am talking about the physiologic development of the brain, it seems that the brain is still vulnerable at your age) .
Furthermore, the Dutch weed is kinda heavy. I have seen some people totally flip on it. Mind you I have nothing against people smoking pot, people drink alcohol too which is in the same category for me and everyone should be aloud to have his or her vices to a certain degree.
But there are limits even for me
