There are a lot of phrasing principles in this Unit. You may find, like arthaey mentioned in the phrases drill here, that you only need to learn what you will use in your life today. Later you may find other phrases helpful and these are good guidelines to know or remember.
You may also find that some of these phrases could be used today. For example, the phrase with "department" you may find useful with "Computer Information Technology Department" or something similar.