A Busy Week

During Last week, I was so busy with my works. Early on (you can omit on but it's fine) Monday morning, I attended an annual workshop. (new sentence) The workshop is held in Ho Chi Minh City, and that lasting lasts three days from Monday to Wednesday. The next two days, my colleagues and I served some guests came from Thailand. We communicated  together in English and more body languages were was also used in that party. We introduced to our Thai friends special Vietnamese cuisine along with more traditional foodsserving served in a cool atmosphere. My colleagues and I also drank [much is not bad but "alot" sound better] a lot of beer in this party.

Where you said "We communicated" (you can also say "We conversed" or " We talked")

When you say " and more body languages were also used in that party." Do you mean that you used hand gestures as you talked? Help me understand better what you're trying to say.

When you say "cool atmosphere" do you mean "relaxed? chill (slang term for relaxed) or do you mean "welcoming"?