How to use UVs on a custom model?

Hi guys
I am stuck on trying to create my own medieval tower.
I found a good cobblestone Texture but the UV thats auto generated does not look natural at all. Are there good courses how i can learn how to change/modify UVs to objects so that the texture looks good? I haven’t found anything useful so far.

For my case: I would like the UV to overlap on the edges and not look change the tiling resolution on the top stones like in the picutre:


I tried tinkerin around with all options in UV.
Projecting a box or a cylinder doesnt get me there. Opening the UV Editor leaves me with even more questions.

Appreciate all the help!