When to create Blueprint project and when C++ in Unreal Engine?
Working with "pure" Blueprint project is simpler and faster, because you don't need Visual Studio C++ installed on the computer and don't need to compile the project. But if you will need C++-capabilities in BP project, you can add C++ class in the project and you project turns to be C++. So, for simple and test projects I propose to start with BP. For "big" project I propose to use C++ project from the beginning, because actually C++ is currently much more supported when BP in Unreal Engine.