The first day of my job

It's is the first day ofon my job. I work in a company as an assistant of the foreign business manager. Our company is mainly engaged in the manufacture production and sales of Jewelry Packaging. Since I am not good at English and have no relative work experience , I am not confident to do the a good job. Actually, my being hired was beyond is out of my expectation. Thus, the job is both a chance and a challenge for me.How was my first day? Fortunately, I am Ok. I could handle my stuff today.In the morning, I sent an Email to a foreign customer according my boss's instruction. And I made some tables via Excel.In the afternoon, I helped with the reception for customers and the Packing of goods. I realized my weakness and low efficiention. when I worked. I regret that I overestimated my capability and didn't studyhard over in the past.
By the way, my colleagues are hard working-hard and ambitious.I will learn from them and keep moving on.

you seem to have very good written skills to me