I've seen those videos. The problem is that I do not have the right tools and a place where to work with them.

I prefer an already made turbine and just install it next to the river.

I would like to start testing with something like this: https://amzn.eu/d/0a7rK4NW

More like testing and learning by doing it. Is a good cheap option and is small. Keep in mind that my homestead place is not easy reachable by car, only by hiking 8km from nearest village, through a forest, regular trail only walking.

I was carrying all the materials in my backpack and is a hell of a job. Carrying a 20-30kg turbine on my back for 3h is not an option.