Good to hear that you have an interest in Bitcoin, 18 years old and already invested on it. Being a courageous to try new technologies, i mean new innovations, crypto investments, thats a good sign for potential high returns in a long term investment.
But take note about the security risks, you have to secure your bitcoin to prevent losses and to be safe from hackers.
Starting at a young age is indeed a good thing, although it's hard to miss out on crypto seeing that the whole world has evolved so greatly that the youth are all indulge in crypto related stuffs one way or the other especially those in the western world. I have also started something for my boys although there are still very small but I am the one doing the savings and the goal is when they get to the right age I know there must have being well exposed to Bitcoin that telling or showing them about it won't be any hassle for me. I believe saving for the young or saving at a young age is key part of knowing someone who has big ideas and dreams.