As with anything, a typical day varies from company to company and from employee to employee. In a typical small business, you spend time on whatever the boss thinks needs to be done. Usually that takes the form of an assignment, like "get me a sales report for last quarter, summarize it into a chart by territory, and make me a presentation to share with the leadership team." With that assignment, you'll need to find the information (which often means checking with administrators and managers in many departments) and then put it all into a presentation. When you show it to your boss, he'll have a bunch of changes, so you'll re-do about half of the work.
A typical day starts at 8:30 or 9:00 with a lunch break; and the day ends around 5:00 or 5:30. Sometimes you have to stay late to deal with some emergency but that should be the exception. A day may be filled with various meetings and whatever "work" you've been assigned. No employer wants to see you on Facebook or playing computer games; you're there to work.
Here's the thing you need to understand: Business work is based on simple economics--Your employer has a problem and you have a skill that the employer is willing to "buy" to solve his problem. In the case of fast-food restaurants, they need people who will show up every day, do whatever needs to be done, and are friendly to customers and other employees. Happily for the employer, those people are reasonably easy to find--and, unhappily for the employees, that means the job doesn't pay very much. After all, almost everybody has the skills to work in fast food.
In the world of supply and demand, higher wages go to people who have special skills. Sales people make more than software developers who make more than marketing specialists who make more than administrative assistants.
The more specialized the hiring requirements, the more difficult it is to find qualified candidates, and therefore, the more employers are willing to pay.