The .emacs.d practice for now is to create a folder named .emacs.d , and then put a file called init.el . Emacs will load this file at startup.
cd mkdir .emacs.d cd .emacs.d touch init.el
In this .emacs.d folder is Emacs, which will host temporary files, packages, etc. that you would not like to contaminate your home folder.
If you are new to emacs and just want to get started, consider downloading one of the existing emacs configurations on github and setting up: