Yes, you can start printing on demand with no money. You can build your own online store using a free platform like Shopify, or you can use a free tool offered by many print-on-demand service companies to help you with fulfilling your orders. When it comes to designing, print-on-demand companies come with free mock-up generators as well as free templates and designs online to use for your products.
If you are a creative designer you can offer designs in the form of digital products to others and receive royalties in exchange. In some cases, a good print-on-demand site will even help you calculate your business costs, and help set a price to help set prices for a cozy profit margin.