Here’s a possible arrangement for the sentences to complete the paragraph coherently:

I just returned to Vietnam after four years of studying in Germany. 1) **B. Life away from home was not easy.** Making friends seemed difficult at first because we came from different parts of the world. 2) **A. German was not easy to master.** However, thanks to my friends there, my German improved a lot. 3) **E. However, I began to like Germany over time.** I usually felt lonely. The food was also different, and I had to cook my own meals. 4) **D. I had lots of exciting experiences when I was there.** It was a beautiful country with nice weather and friendly people. Although it snowed a lot in winter, the roads were safe to drive on. 5) **C. Besides, I could improve my skills.** For example, I learned to look after myself and how to work with other people.