As you are likely aware most private passenger auto insurance policies do not provide coverage when the covered vehicle is used to deliver property, i.e. pizzas, other food, package or people for a fee (salary, tips, etc.). A normal personal auto policy (PAP) sold to individuals usually excludes coverage for drivers who use an insured vehicle to transport persons or property for a fee.
Coverage would probably be denied if an accident occurred while you were using your personal vehicle to deliver food, packages, etc without your insurance company knowing about you using your car for business purposes and stating that your vehicle would be covered. If you not an independent contractor and have an employer, check with your employer to determine if the company will provide you coverage while you are engaged in that employer's work.
Commercial or business driving rates, delivery services, newspaper carriers and real estate agents fall into this same category, are higher than those in standard PAP policies.
Since most personal auto policies will exclude coverage for the vehicle while it is being used for "business purposes" you will likely have to obtain a business use or commercial policy for your vehicle since you will be delivery property for money.