Sorry for the so late response!
I assume you've read the README
file available with your install.
I also hope you've found the OJS Documentation
Usually, certain questions are answered in specific forums. This is one page
I've found by searching Google with "setting up apache with mysql on centos".
Change the database to the server you plan to use, but only PostgreSQL and MySQL have been fully tested.
I'm not really fond of CentOS because of its perks for setting up web servers, the places where it installs things is different. Just a matter of knowledge...
Ramón Martins Sodoma da Fonseca
Executive Editor of Ciência da Informação
Analista em C&T
Coordenação de Tecnologias de Informação
Instituto Brasileiro de Informação em Ciência e Tecnologia - IBICT
Ministério da Ciência e Tecnologia - MCT