Apache settings of: mpm_worker, mpm_event, mpm_prefork, php-fpm and switching php versions

Apache settings of: mpm_worker, mpm_event, mpm_prefork, php-fpm and switching php versions

what is best setup 512 ram vps, running 1 joomla site atleast less 40 visitors a day??
just run needed features to run a site, mail not installed..
a advice would help..
whats the recommended mysl.cnf tuning?
thanks