Entrepreneurship definitely matters the most when it comes the a startup, or his/her first time.
So... here is just a quick overview of some important things to know when you "become an entrepreneur":
Putting too much time into a business plan won't usually get you anywhere. In fact, many entrepreneurs often make this mistake, and end up wasting a lot of time and money.
After validating a business idea (there are many more in-depth ways to do this) and building your business model hypothesis (sorry for the jargon), it is important to quickly test out the target problem that you are trying to solve with your service/product, and pivot/proceed from there.
Topic wise, it would definitely benefit and ease your first entrepreneurial experiences if you have some background in computer science, marketing, or finance. However, these skillsets are definitely not required to be a successful entrepreneur.
In entrepreneurship, there really isn't a way to "fail". As long as you take initiative and consistently maintain your ambition, you can build a sustainable business.
I hope this helps your decision on choosing a business/non-business major!