MYSQL_SET_CHARSET_NAME option usage

Hi, As latin1 is the default character_set used by the connector C , I would like to use the MYSQL_SET_CHARSET_NAME option to change it to utf8. Is is the right way to use a my.cnf file to set it , even this file doesn't exist on my server (mariadb server I want to address is running on a remote server) ? If positive , under which [ ] do i have to set it ? Thx for help. Regards, J.P.