Translation of let's see in German

Your ask why i am learning English ? I made a trip two years ago, a vacation in a foreign country and I could not speak with other people. That was very bad for me. When I came back home I began to study English.
Hey. You are online! Pollution means that the air is filthy and that it is hard to breathe. I'm getting much better at German, so please correct me when I am wrong in my language. You're English is actually great.
At noon we continued to the Altiplano to visit some lakes and volcanoes. At 4000 meter above see level it became suddenly extremely cold and our heads started to spin. Altitude sickness?