When the Dragon Boat Festival was over, it was a sign to get ready for school again. Looking back on the three-day holiday, I felt a mixture of excitement and tiredness. [My friends followed me to my hometown]. Out of the blue, I ran into my foreign teacher on the train. I was a bit nervous because my oral English is not that good, but I was more confident/comfortable after we had lunch. He was so kind. I know that Jewish people usually pay the bill and it is rare for them to split the bill, so I took advantage of it. By the way, my foreign teacher is from California, USA. During the short journey, I had a hard time because I could not express myself clearly, but I made it, and I'm in school now.

*I tried to keep it as close to your version as I could, so as not to change the meaning too much.

[My friends followed me to my hometown] - Is this why you were excited? Were they on the train with you when you ran into your teacher? I am not sure where this sentence fits into the picture.

Good job. It sounds like you had fun and got free lunch :)