You don’t need any origami tools to fold paper. All you need is your hands, a piece of paper, and a flat surface to fold on. Easy. You can do it at home, you can do it at work (oops, did I really say that?). You can do it on the train, you can do it on the bus. You can do it in a coffee shop, you can do it in a restaurant (see dollar-bill origami and napkin folding or all instructions).
That being said, your paper folding experience can be more fun and easier with some select tools. Here are some things that you may want to consider.
You may be interested in reading about how people design origami and the different ways you can teach origami. For example, is it better to have written instructions, photographs, diagrams, or videos?