Dear Amber,

It is a pity you have not been able to find a spiritual director, it would be really helpful. Please let me know where you live, and I may be able to put you in touch with someone.

The best preparation for the future is the present, keeping the future in mind. That may sound a little trite and abstract, but let me put it this way: what you are looking for in your life is to know God's will in order to do it as best you can. You are fairly certain that he is calling you to the contemplative life in the future, although for now you dont know exactly what order or where. Now, God's will is a continuum, one step in our lives is a preparation for the next, so what God is asking of you now is the step he will build on as he opens his plans to you in the future. You dont know the details of his will in the future, but you know plenty of details as regards your present, and you know enough about the future to figure out some additional details in the present. 

As regards living God's will in your life now, what is very clear are all the normal duties of a young woman your age (studies, home, etc), so I will leave these without comment, and focus on the vocation-related aspects of your life.

Live your life as a constant conversation with God. Not that you will be actually talking to him all the time in words, but let your actions talk for you: do everything to please him, do it in the way that will please him more, and serve him in others. When you pray, offer up what you have been doing and what is coming next. Live simply and trustingly knowing your life is in his hands.

Second, take responsibility for your call now. This doesn't mean that you have to up and leave and join a convent immediately, but it does mean saying yes to Jesus in your heart and making your vocation the priority of your life. Make sure you to do everything that will help it (getting to know the three orders you mention, reading lives of the saints from those orders, visiting them, finding out the conditions to join as regards age and studies and speaking to your parents about your vocation), and avoid anything that could damage it. Think of your vocation not as something you will do in the future, but a path you are already walking on each day.

I hope these two ideas help you, and be sure of my prayers.