Two major differences between ‘macro’ and regular lenses are that the macro ones have a flat (or at least flatter) plane of focus, and a relatively short minimum focus distance. If you plan to use a non-macro lens, look up the minimum focus distance of your lens before you start.

If you have an F-mount Nikon, have a look at the 28-105mm 1/3.5–4.5 D series lens. It has a normal/macro slider switch which, when actuated, brings the minimum focus distance in to 213mm and the minimum focal length to 50mm. They’re on eBay for around US$100. They’re built like a tank. I’ve been using mine since the late 90s.

Whatever camera, you are going to need a camera support system — at a minimum a pile of books and a beanbag to nestle your camera on top, or maybe a tabletop tripod (most normal tripods won’t let you get low enough).

Happy shooting!