Most starting businesses lose money for the first couple of years, and many of them lose money for years after that. You really don't have enough starting capital, unless someone else is going to support you and the business for the first couple of years, or unless you have another job and treat your startup as a second job.
"Being your own boss" means that you will have no vacations for years. It also means that when an employee can't come in, you have to do your work AND the employee's work as well, if you can't get someone else to cover. Those people who think that "being their own boss" means that they can slack off or not work when they feel like it usually end up without a business, and heavily in debt besides.
Different business fields require vastly different skill sets. For instance, retail stores require customer service skills, and if you don't have them, then you won't be able to teach them to your employees. It's a mistake to think that just studying business will magically grant you the knowledge you need to open and run ANY kind of business. You will need vastly different skills to run a used book store, for instance, than you would to run a lawn care service.
There are some skills that are basic to all businesses, such as principles of accounting and marketing, but I assume that you're taking classes in these subjects as part of your studies.
