The foundation and structure of DomacsVim is based on Vim and NeoVim. So, for ease of work, it's better to have a basic knowledge of modes, default editor commands, globals, mappings, etc.
To get an overview of Vim, you can run the following command in your terminal:
$ vimtutor
To get an overview of Neovim, you can run the following command inside Neovim:
:Tutor
Domacsvim is written with lua programming language and you definitely need to know the basics of lua language to configure or cooperate in it (it's not difficult).
:help lua-guide
Or check the official documentation