There are products out there that are essentially stages in miniature –a white box, with lights all around it and a place to put your camera –probably worth looking into.
Lighting is probably the most important part of taking good photos. If you don't want to pay for any equipment, create a (probably white) backdrop and take it outside during the day. This is the cheapest way to get good lighting. If you have a decent smartphone camera, you can probably get away with just a small tripod (amazon sell off-brand Gorillapods which are quite cheap). The only thing you'll have to be careful with, in this setup, is shadows.
Knowing how to use Photoshop would also be a plus, for clearing up any issues with the photo, and improving the colours/brightness, etc. As a career designer, I hate to say this, but there are probably people on Fiverr that will do this on the cheap.