A lot depends on your circumstances. Are your parents really strict JWs? Are they loving parents, but just misguided by the religion?
Are you still in school? If you are a senior in high school, start making plans to go to college. Contact a guidance counselor and see what it will take to get an education. Most of us didn't go because of being JWs, it's something you really need to do if you want a good job.
You may have to wait until you are older before you can leave the religion. Start preparing now for when you can be your own person. Obey your parents but earn as much as you can about the religion, so that you know what to say if your parents don't understand why you do not want to be a JW. Make sure it's for the right reasons, not just that you want to do things they don't allow, but because you don't believe it. It's important to be clear on that. If you just want to party, then your parents will not be OK with that and it will make it harder.
Once you are a legal adult you can tell your parents that you are not going to be a JW. They may be upset, but there is little they can do if you are resolute. It's your life after all, they chose their religion, you didn't.