Choosing the career one wants to pursue is a decision that some make much earlier than others. Of course there is really no specific time at which you must make the decision to choose a particular career - the only thing is that the earlier you can do it, the better. Choosing a career is something that you can start in high school, college or even when you graduate. You can even defer your decision to settle on a particular line of work until after you have already started working. What is most important is the process you use to settle on a particular line of work.
First, you need to establish your likes. What do you enjoy doing? Is there something that you do, that you would not mind carrying out even if you did not get paid for it? If there is, think about how you can do that for a living. It must be said, though, that not everything you have a passion for can be translated into a sustainable source of living.
Next, you should assess your strengths. What are you really good at? Note that this is not the same as what you are trained in. This could be something you can do even without necessarily going through extensive professional training. You can identify your greatest strengths in several ways. One of the most effective ways is to take note of any skill that people around you are always commending you about. If the people around you think you have an exceptional strength in a certain area, try to find a way of monetizing that strength into a career.
Then, look at your credentials. What are you trained in? If you have gone through nursing school, then the most logical thing to do would be to apply for a nursing position. This might seem obvious but it is an important point to note. Some people opt to try and get into careers in which they have virtually no training.
Even when you are following your passion, if it is not an area that you have any formal training in, then you might want to first go into the area you have already been trained in and then find a way of transitioning your way into your preferred career. You can attend evening classes and then move into your new career once you have the formal training to back up your interest. That will increase your chances of finding a job and also ensure you still have a steady source of income before you make the big change to your new career.
Consult with others when selecting the career that suits you best. Things are not always what they seem. So take time to talk to family, friends and professionals already working in your career of choice. This will give you a more realistic view of just how things are done day-to-day and this will then inform your decision on whether to make the change or not.