It's ok to be unsure with what you want out of life. Take some time, discover you passion, work hard at your practice, and before you know it you'll be writing down a list full of life goals. You will faces failures, be told no, but overcome adversity never give up! Life is about overcoming obstacles and learning how to adapt to new situations.
Deciding what to do with your life does not happen over night, it is not something someone else can decide for you, it has to come from within.
If you have an idea or passion then just go for it, we only regret the things in life we didn't do and the chances are, if you don't do it today, someone else will tomorrow. Don't be afraid of failure or striking out. A lot of people go to university and discover it is not for them, whether than just be the course itself or university entirely. However, then they are to ashamed to drop out because of the judgement for others, but this is when you have to just do you! Decisions like this are what separates your life, from merely existing to actually living. The same with a job, if you don't like it and feel like your wasting your time, find something else and quit. There is nothing wrong with starting over. Keep adjusting and trying until you discover your passion/what your good at. No one is keeping score of how many set backs you've had because everyone should be focused on their own journey.
Just remember to always stay true to you and listen to your instincts as they are what will make you know what you are doing!