Some good advice, but mostly technical. If you are going to own the business, then you must be a business person, not a technician.
There are some great business books and some detail training facilities also provide very good and solid business and marketing training as well.
For example, we will soon offer tinting, but I can't tint at all and have no interest in tinting. However, we will offer it with very high quality and I'll make money from it.
You need to sit down and write up, even if basic, a business plan. This helps you focus your company and avoid spending here and there and hoping you hit your target.
This is just a brief response..there is more. PM or email me if you want to discuss further.
Good luck,
Rob Regan
Santa Barbara, CA