Hello:
My name is XX.i am 18 years old.it is said that you came to China from Germany.Welcome.
i really hope that i can make friends with you and get along well with you.i can't speak English well.if we become friends ,i think we will be able to exchange the phone number (或the way of contact 不过,这样说有点复杂) ,communicate with each other and you will help me with English.my phone number is xxxxxxxx.Looking forward to hearing from you.
it will be nice of you to be my sister.(建议删这句)
a Chiese boy who wants to make friends with you.
yours sincerely （二选一）
开场：excuse me (删吧),i want to make friends with you .so i wrote to you to express my faithfulness.
德国人的英语也不见得好吧（当我没说）