Thank you for your question.
I’d like to emphasize from the start that there is a basic precept in Islamic law that is important for all Muslims to remember. That is that at the core of all matters is permissibility.
God created the universe and everything in it is essentially good. There are, however, a very few things in this life that are forbidden, or haram.
These are matters that are to be avoided completely, and we should avoid all roads that lead to them so that we minimize the chance that we fall into haram practices.
When it comes to halal and haram in Islam, the general rule, therefore, is that everything is halal, except what God and His Messenger have explicitly commanded us to avoid. By explicit I mean that the issue is named specifically in the Qur’an, and/or explained to us by Prophet Muhammad, peace be upon him.
For example, in the Qur’an we find stated that worshipping other gods or associating partners with God is forbidden; eating certain foods and drinks; joining certain people in marriage; dealing in business involving usury; adultery and fornication; lying; bearing false witness; cheating; stealing; murder; and making haram what neither God nor His messenger have made permissible.
With each of these a specific punishment is associated that has been stated by God Himself, or by Prophet Muhammad, peace be upon him. They cannot be determined randomly by others or by an angry mob.
There are many Muslims who choose to take the opposite perspective; that everything is haram and only a few things in life are permissible.
This is a very difficult foundation to base our lives upon, and it is not something that can be sustained for very long. It has also not been asked of us by God or by Prophet Muhammad, peace be upon him.
Many newcomers to Islam, having not grown up in a Muslim family, feel that they must be “more Muslim than the Muslims”, so to speak, and become very conservative in their practices and perspectives.
Islam is designed to make our lives easier, not harder. Make sure to follow what God and His Messenger have said, not what the average Muslim thinks is halal/haram.
“…God wills that you shall have ease, and does not will you to suffer hardship…” Qur’an Chapter 2: verse 185
Regarding your question about working in an office around men and having to sometimes be alone with your boss, there are ahadith that deal with the matter of a man and woman being alone together who are not blood relatives.
Men should not enter the home of a woman if a male relative is not present. If a man and a woman are alone in a room, the devil is the third among them. Prophet Muhammad did not specify any punishments for these practices, so they should be taken as strong warnings to avoid these practices and falling into greater sins.
A general rule that is mainly a cultural saying may also help you to lead a pious lifestyle as a Muslim: Fear what is hidden from the eyes of people, not what is in plain view.
Practically speaking, if a man and a woman, for example, are having a conversation in public, and within earshot of anyone who may be near, they are not likely to be discussing plans to commit sinful deeds together. If they are in a secluded area or room, away from the eyes and ears of people, then it is natural that people will become suspicious.
If your work involves meeting with your boss or other male staff members from time to time, it is not likely that any discussions or practices involving haram will be taking place.
If, however, a man attempts to take advantage of his business relationship with you by words or deeds behind closed doors, it is very important to immediately warn him against doing so or to report their behaviour to the authorities as soon as possible.
A Muslim woman is not someone easily taken advantage of. She is a strong-willed person who fears only God, and does not allow anyone to take advantage of her or tarnish her reputation.
I hope this has been helpful to you. Please keep in touch.