Translation of Lehrstelle

I try to learn English as much as possible so that I can travel next year to the United States. I would agree to your proposal but I also need to find good teachers. My goal is quality and speed.
How is the weather in Hamburg? We have 15 degrees and some sunshine here in the south. I have some remarks on your mail. If you write again and if you wish, I can correct your spelling mistakes.
I am glad that you accepted my offer. I would like to write letters and emails in English and if you want you can write back to me in German. I want to correct your German and so we will both get better.