Unfortunately getting close means spending money for macro lenses. I did hear of a very cheap and cheerful method of getting close-ups and that was using a magnifier on the front of any existing lens. My son used to have one but for the life of me I can't remember who made it. It was seriously cheap though and although the pictures you could get through it were usually rubbish, there was a sweet spot where objects were in focus and pretty clear.
Although I've never tried on them on modern lenses, there are things called extension tubes which have no glass but extend the focal length of any lens. They are a b****r to focus, so small is the depth of field, and I'm not sure they work that well on modern AF lenses.
In days gone by when I used a Nikon FM2n there was a method I occasionally used wherein I turned a 50mm lens round and using an adapter fitted it back to the camera making a close focus lens, it worked reasonably well but I don't think you could do that these days.