If you have any crafting skills, or if you can make food of some kind that's fairly portable and doesn't need refrigeration, and you have access to someplace where you can park with your wares and bother passerby, that might work. I once made about $30 sitting in a hallway at school for an afternoon selling muffins for a buck fifty each (I was on a muffin-baking spree, and my freezer was getting full), and my town has a fair number of street vendors in nice weather (I have bought things from them before). If the only problem with cashiering was that you weren't supposed to read, this doesn't seem like it would present any problems for you, since, who's going to stop you?

Some places might require you to have a permit; I'm pretty sure the street vendors have to get one every morning from town hall. Nobody bothered me when I sold muffins and I didn't have any kind of permission, though.