How to Quit an Agency and Start a Business

I was studying engineering, but when I started engineering, I was already just started to listen to your stuff. And so I did like a side hustle and now I quit the university. And now I'm doing full time entrepreneurship, you could say it. So the business that I came up with is a service where I find the customers online or like I have an agency that finds does social media marketing and it's a sharpening service. The idea is to in the long term, get rid of the agency, do the marketing to sell because right now I'm not owning my customers. They own the customers. It's kind of like an Uber thing. How old are you? I