There are a few businesses that might work for a person in your position. Self storage might be a good fit, especially if there is a house on site that you can live in. Not a super romantic place to live but it is a decent business with steady cash flow and billing is all automatic. Another option is some sort of personal service type of business but those usually require some technical skill. I know people who do book keeping out of their homes and make good money. Small businesses will pay $50 an hour for someone to do their books, payroll, etc. and you can work from a home office. I have friends who have become investment advisers and done well. Real estate is another gig that some people really take to and doesn't require a huge investment to get into. A small locksmith business could make money and wouldn't be too physically challenging. Selling cars can be a nice job for a semi-retired car guy but I don't think I'd want to buy a dealership.

There are some important factors that you need to think about besides just how much money you have and what your cash flow requirements are. Small businesses run on personal relationships so you need to be honest with yourself about your interpersonal skills. If you don't love to meet and greet strangers all day long then stay out of any sort of retail business. An introvert will go broke very quickly in a sales type environment. If you're an introvert then focus on something you can do remotely such as PC programming, PC repair, etc. If you love sales and people then get a business where you are meeting people all day long like retail store or a restaurant.

My dad lost his job in mid-life so he went and bought an upholstery shop from a guy who was retiring. My dad didn't know anything about upholstery but he was lucky to inherit a really good employee who taught him the business and helped him make money. My dad then went on to buy a paint store and he did okay with that. My dad loved to talk to people and he treated everyone who came in the store as an old friend so he was successful even though he didn't know much about the business before he bought it. But that trick won't work for many people. Some people just hate talking to strangers and that attitude will sink a store in a heartbeat.

Good luck but you need to figure this one out yourself. You (or your wife) is the only one who knows what you want to do and what you would be good at.