Buying would not be a problem. The steer is most to straight on smaller bikes which makes it difficult and more tiring to control. You should be able to stretch your legs on the pedals throwing your knee backwards or you will lose strength in your legs making it even difficult to stand up from a chair. This is very important. Half your foot should touch the ground standing still. This is minimum safety because roads are going down to and are sometimes bend towards the sides.

Try finding the address of the place where you could rent a bike and ask them to have a good option for you when you arrive. Same goes for shops.

You will be fine, All bikes are adjustable in size, Normal adult bikes are 28” size.
I think you would need the smallest adult bike (26”) that is the size most dutch people move to at age 10-12. And if that doesnt fit (it should though), they will have a childrens bike for you. Childrens bikes arent all cute looking and pink, they usually look like normal adult bikes, just smaller

You can probably find a good bike because there are also bikes for ‘children’. The bikes for older children don’t look so much different from ‘adult’ bikes but are just a size smaller.

Not all the Dutch are tall and there are also a lot of people from other country’s living in the Netherlands who are not so tall. So there are plenty of bikes, all sizes.

You should be able to adjust the seat and the handle bars to your height.
Or you could just get a kids’ bike?