How to create a new file using Vim and save it with desired filename
First of all, let's start vim:
$ vim
Now we can edit file. To do it, we have to change to write mode, so just click "i":
i
Now we car modify file the way we want. Let's add a string.
And now click "Esc" to go out of write mode.
In order to save a file, type
:wq test.txt