Great advice so far. Here is what I would suggest you do before buying anything:
-Mount the 18-55mm kit lens
-Set camera to Av mode and f-number between f8 and f14. ISO should be low as possible, but you can have it set to Auto 100-1600 for now.
-Switch camera to MF - Manual focus.
-Zoom lens to 55mm, and twist the focus ring to the closest possible focus (one side of the focus ring is infinity, the other side is nearest possible focus. You always get the maximum magnification at the closest focus)
-Now simply leave the focus ring alone and come as close to the object as you can, until it appears to be in-focus. Move back and forth, but don't change the focus, leave it at minimum. Slowly press the shutter and take that photo.
That is not quite *true* macro (macro is usually 2:1 magnification or higher. Modern Pentax macro lenses go to 1:1, older ones need an extension tube to get that far), but it is pretty close!
Bonus points if you have a tripod and use 2sec timer (and ISO 100, if you have enough light or the object in frame is stationary). This is good practice to know what to expect with macro. You can also get some old Pentax 100mm macro lenses fairly cheap, almost as cheap as a good set of Raynox filters:
https://www.pentaxforums.com/lensreviews/showcat.php?cat=all&stype=1&si=macro
These can double as general portrait and tele photography lenses. The older ones are manual, but with macro you won't be doing much focusing anyway (with macro, MF is usually the way to go)