Growing up in Egypt, it was hard to come by photomicroscopy equipment, because this was only available to research institutes. For an individual, it was unusual to take this as a hobby.
I initially was exposed to microscopes just reading books about biology, botany, and like subjects. Photos of interesting things intrigued me into seeing for myself what things look like.
A cousin of mine got a toy microscopy as a gift from his father. I recall I borrowed it to see what I can see. I also went to visit a relative who worked as a university professor, and had lots of microscopes with fancy features, such as an electric light source, polarizers, X-Y moving trays, double eyepieces, and more.
Later, I was determined to get a true microscope. I found a scientific supplies company selling a Russian made Biolam microscope for a really cheap price: 75 Egyptian Pounds! I got it and I was really thrilled.
Of course, it did not have an electric light source, nor a moving tray, but it had good optics, and that is what matters most.
I had an machinist whom I know make an aluminum microscope adapter forthe cheap Zenit camera that I owned. This was fairly easy, since it had a thread mount.
Exposure was mostly guesswork, since the camera did not have any kind of light meter, neither external or internal.