You need to look presentable and smart on your first day of work. Sometimes during introduction before you report for work, you are told the type of clothes that you are supposed to wear to work. Follow the instruction given on the dressing code. Some people are not told what they are supposed to wear when going to work. Put on the type of clothes that your interviewees wore on the interview day in case you were not told how you are supposed to dress when coming to work. So in case you do not have an idea what to wear, look at the setting of the office and choose the clothes accordingly.