mpd config file /etc/mpd.cond should be customised, at least a path to
music directories (music_directory).

To use alsa sound output instead of pulse, activate the corresponding
part of mpd.conf and put comment on pulse part.

For security reasons, MPD runs as restricted user mpd, group
audio. Please consider that music_directory and all directories in the
path to it should be readable and executable either for user mpd or
group audio. IF you ask youself what should "executable" means to
a directory, it is a right to change into it. So a directory could
either belong to mpd user or belong to the audio group or be readable
for all (others). Directories and files beneath it should be accessable
the same way. Some examples for right permissions:

ls -l -d /mnt/mp3

readable by everyone
drwxr-xr-x  226 user    users       16384 Mar 24 23:36 /mnt/mp3

readable by audio group
drwxr-x---  226 user    audio       16384 Mar 24 23:36 /mnt/mp3

readable by mpd user
drwx------  226 mpd    audio       16384 Mar 24 23:36 /mnt/mp3

If you would like to set up some independent directories, declare one
of it as music_directory and link others in it. Permissions for other
directories are to be set accordingly. 

MPD will be bounded to the local address (localhost): If you would
like to control it over network , then change bind_to_address to the
network address. You can set password and the list of activities to
restrict control of MPD over network.

To start MPD at boot time, call as root:

systemctl enable mpd

If filenames or directory names don't display correctly, set the
character set (encoding) for the filesystem in mpd.conf.