I need help for Debian and Centos server.

[elenh]

Thank you.

Run these commands:
updatedb
This is for both os? : find / -name my.cnf -print
this for debian?: nano /etc/mysql/my.cnf
this is for centos?: vi /etc/mysql/my.cnf

Where and how i put it?: max_connections = 500

find / -name php.ini -print
nano /etc/php.ini
vi /etc/php.ini

where i put it?: memory_limit = 16M

(How excactly do i that? after the command vi /etc/mysql/my.cnf i get some lines and at the end they say INSERT only and i dont know how i continue..)