For this to happen, you need to put your best foot forward and we would expect you to adhere to the rules and regulations that govern the professional conduct here.
The working hours are fixed, though, you may come in a bit late with the prior permission of your manager. Do remember to inform your manager in advance so that the customers do not have to wait at the counter or in your office. You have to ensure that you abide by the timings and if you have put in extra hours, you can claim overtime for it. Note that overtime does not apply to the managerial cadre.
Your attire must be professional and it must not be flippant or causal. Men are expected to wear ties and optionally a jacket or a suit. Women are expected to dress professionally in business suits. No jeans or sneakers are allowed on all days. On some Fridays that are specially designated, you may come in casual attire. These days would be intimated to you in advance and most of the time there would be some fun and frolic along with celebrations of special occasions in the office. You are not allowed to have food or drinks at your work seat. There are designated cafeterias for these.
You are expected to be civil with the customers and put up with minor irritants in their behavior towards you. However, you may raise the issue with your manager if you feel that a particular customer is behaving badly with you.