Chào em, em tham khảo:

Dear [Friend's Name],

I hope this email finds you in good health and high spirits. I am thrilled to hear that you will be visiting Vietnam soon, and I can't wait to show you the wonders of my hometown/city. Get ready for an unforgettable day filled with cultural experiences, delicious food, and breathtaking sights. Here are some must-visit places and activities that I highly recommend:

The first one is the Old Quarter in Hanoi. You can immerse yourself in the bustling atmosphere of the traditional markets and explore the narrow streets of Hanoi's Old Quarter. You should bargain for unique souvenirs, handicrafts, and local delicacies.

The second one is Hoan Kiem Lake in Hanoi. You should take a leisurely stroll around the picturesque Hoan Kiem Lake in Hanoi, where you can witness locals practising Tai Chi or enjoy a cup of Vietnamese coffee at one of the lakeside cafes. 

The third one is Temple of Literature in Hanoi. You can explore the rich history and culture of Vietnam by visiting the Temple of Literature in Hanoi, Vietnam's first national university dating back to the 11th century. 

Remember to embrace the local customs and traditions, and don't hesitate to interact with the friendly locals. Vietnam is a country of warm hospitality, and I'm sure you'll feel right at home.
I hope this guide helps you make the most of your day in Vietnam. If you have any more questions or need further assistance, please feel free to ask. I am eagerly looking forward to showing you around and creating unforgettable memories together.
Safe travels, and see you soon!

Warm regards,
[Your Name]

Chúc em học tốt.