As a beginner you sometimes have difficulties with software packages and their inner dependencies. This is normal.
An easy way is to use a local server and then drop the modules as you wish. In the beginning you need only very few of them.
Have a look at the instructions at the bottom of the Collection of examples from discourse.threejs.org page: * discourse.threejs.hofk.de
As editor you can use a simple text editor. Or something like Notepad++ portable.
Good luck 