/var/www/html/
so you can uncompress the software there, but you can do it where you want if you take care to allow Apache to access that location. Now you have a directory called /var/www/html/phpMyCatalog
or something similar.
chmod 777[phpMyCatalog installation dir]
to achieve it.
The file initialize.sql
should have the same permissions:
chmod 777 [phpMyCatalog installation dir]/initialize.sql
You can change permissions for directory and files as well with your fauvorite file manager.