You can use EasyPG Assistant without any Emacs or GnuPG configuration whatsoever, for example to encrypt and decrypt files automatically with symmetric encryption, see Encrypting and Decrypting gpg Files. However, to use the full set of EasyPG Assistant’s functions you should have at least some minimum GnuPG configuration in place.
John Michael Ashley’s GNU Privacy Handbook, available online as part of the GnuPG user guides, provides an introduction to GnuPG use and configuration. In contrast to that, the GnuPG manual (see Top in Using the GNU Privacy Guard) is more of a reference manual.
EasyPG Assistant commands are prefixed by ‘epa-’. For example,
EasyPG Assistant provides several cryptographic features which can be integrated into other Emacs functionalities. For example, automatic encryption/decryption of *.gpg files.