Translation of nonserious in German

So by age twelve, I had decided that I wanted to learn English and I was studying for the United States TOEFL at age twenty. Being bilingual practically from birth, makes speaking languages very easy for me.
Take your time to answer me, do the vocabulary exercises and measure your progress! Your answers will be kept in the system itself. After that you can look at the statistics. That's pretty cool here.
The prices for one ticket for category number 2, in row number 15 is what I have told you on the phone (about $ 500 per ticket). Tickets are in block D5, with balcony, all tickets are side by side.