Not really a recommendation but a few things to think about when considering your next step:-
i) What is your intended subject? For static subjects like flowers extension tubes will be fine but for insects a short lens on tubes can be frustrating because the front element will need to be very close to the subject (which will often just fly off). this is why most macro lenses are around the 100mm focal length range.
ii) For very small subjects (micro rather than macro) tubes can be good used with a short manual lens reversed on the front of an extension tube using a home made adaptor made from a couple of filter holder mounting rings glued together. A very cheap but effective way of getting extreme close ups. An old 50mm lens from a 35mm camera is ideal for this.
iii) Photographing large insects like butterflies and dragonflies is very much like photographing small birds and the same gear can be used to get perfectly acceptable results.
iv) In my experience almost all macro shots are taken using an almost entirely manual setup. The technique is usually to get everything set up and then slowly move the camera back and forth to bring the subject into focus. A fully manual lens is actually an advantage for this. Auto focus and exposure can be counter productive. Using auto ISO with a limited range can accomodate any minor changes in conditions.
The above is based on many years of dabbling in macro photography though it has always been a bit of a fringe interest. I use a 35 year old Tamron 90mm macro lens (which I have owned from new) which has been fitted to a number of bodies, currently a Lumix G80 MFT example which gives the added benefit of doubling the magnification given by the lens. Hopefully the attached picture will give an idea of what I can get with it but as this is the first time I have tried to add a photo on this forum it might not work first time.