I want to support an existing business by providing services in the area where they lack so that I can get a business for myself.
What you're talking about is starting a business with the first customer already identified.
You could even make the sale and sign a contract before you start.
This is a great way to reduce the risk in doing something new.
For added advantage, see what you might do to recycle the systems and efforts created for this business to the benefit of other clients.
Then you get something that can really grow.
If you'd like to brainstorm, set up a call.
Supporting an existing business is a great way to test the market demand for your services. If you contract with an existing company as an independent contractor (rather than diving in and buying part of their business), you maintain your autonomy, test the market, and keep yourself open to deciding in the future if you want to invest in the existing company or truly branch out on your own.