Most charities will be delighted if you make a time commitment. That is, if you spend two hours every week, let alone every day, they'd be very happy. They are always short of volunteers. Even if you do nothing but sweep up and clean up, or file things, or answer phones, that will be a great help to the charity.
I've done things like volunteer to reshelf books in my local library. The area libraries are also always looking for people to "read the shelves", which is the term they use for people who just check the shelves to see if any books or other materials have been put in the wrong place. These are easy to do, and they are a big help to the library, an incredibly big help. The local animal shelters are always delighted when I come in to help clean up the places. SOMEBODY has to scoop cat litter and walk the dogs. Again, it's something that's easy to do, and they need people to do it regularly.
Some charities do things like have people gift wrap items in stores, and the people who have their items wrapped make a donation.
If you try to sell home made food, be aware that most cities and counties will require you to have a foodhandler's license, at the very least, and might also require that you prepare foods in a commercial kitchen, not a home kitchen.