Remember that with your age, your parents will need to co-sign for you. You have not mentioned a job so I assume you don't have any reportable income. You also state you want to spend MORE than one semester abroad. That gets costly. You will want to travel and see things abroad that will require you to spend money for "normal" housing and also for housing when you travel.

As for your parents using your card when they build their house, that will probably, for the most part, not work. Building a house means spending thousands, or tens of thousand dollars at a time. Because of your lack of income, you will probably have a very low credit limit that would not cover house building expenses.

As others have said, reward cards tend to require very good credit - and if I recall correctly, you don't have any significant credit history that has been reported to the credit agencies. Your best bet is to, in the short term, change your banking such that you can get a rewards earning debit card. After probably 6 months with that bank AND their debit card, apply for one of the reward cards WITH that bank. Don't worry so much about what miles you earn but about building your credit rating.