One possible version:
Dear Peter,
I’m writing to ask whether you are able to do me a favor.
I want to have a pen friend, hopefully a girl in her early twenties, and with interests similar to mine.
In my mind, she is someone who is interested in travel
ing and having sports. Besides, it would be better
for her to have a pet dog as I have kept one at home for some time. With such a pen friend, I think I
can share with her our traveling experiences, taking care of pets, or whatever we have in common. And
I believe I will improve my English by doing so and learn more about her country.
I’m looking forward to hearing from you soon. (106 words)
Best regards,
Yours
Li Hua