First, I'd get the diploma, that can make a world of difference with multiple things. Just get the diploma.
Second, if you would like to be an entrepreneur, (one who operates a business by themself) you need to find what it is you would like to do. Find your niche, something you love doing. to start, I would recommend spending time practicing the niche you are interested in: gain experience, learn about the industry. After you have experience, you need to know this: Question 1, what is your product and/or service? Question 2, why would people want/need this product and/or service you created? Question 3, how will you deliver this product and/or service?
Let me give you a few examples. coffee: people don't have coffee machines in their house, so they buy one whenever they're out, and they feel they need one.
A gym: people want to exercise, but they don't want to have to pay thousands of dollars for a treadmill, or all the weight lifting equipment, and to have it in their house. So they go to a gym.
Automotive repair: not everyone has the tools of knowledge, so they bring their car to a mechanic.
so you need to brainstorm what you would like to do, and if people would value your product or service.