Dear (имя друга),
I'm so happy to receive this letter from you! What college have you choosen? Who are you going to become? I'm interested.
After graduating from high school, I think, I would like to go to the prestigious university! I'm fond of Literature and foreign languages. Probably I will become a translator or a journalist abroad. If I don't get accept, I will try the next year and spend this one working somewhere and earning my own money. But, of course, I hope I will get accepted.
I'm so happy for your dog! How have you named her puppies? I think they are very nice and sweety! Send me a pic of them with her mom!
Sorry, I need to go! Write me as soon as it will be possible!
Sincerely yours with best wishes,
(свое имя)