One of the businesses you can start from home today at almost no cost is a consultancy.
Most of what you'll need for this comes down to having a smartphone and a computer. Possibly, a webcam. These might be things that you already have.
At best, you might also need a headset of some kind. Possibly, a microphone. These things aren't super expensive and I'll have links for recommendations to them in the description below since you can buy those things, but this isn't overwhelmingly difficult if you have knowledge in a specific area.
You can do a number of creative things.
You can do graphic design.
You can do photography.
These are service-based creative businesses that you can do at home, and all you have to do is invest in whatever the equipment and skills are to execute on that and market yourself well enough. Whether that's locally or online.
Another business that you can start from home, believe it or not, is a tech support based business.
Tech is not entirely the same as consultancy because of the expertise it requires, and the level of execution involved, and there's a little more nuance than detailed things to it.
So I would say that it's very different from consulting just because of how involved or ingrained it can get, and I would say that you can have a tech-based business from home doing some very specific stuff, and that might involve doing things on the programming side. It might involve technical sport and customer service.