When you install MySQL on CentOS 8, you will need to install other associated packages as well. It can be easily solved by @ option when you call yum command.
Following command line will install all the associated packages at one shot.
If you haven't installed PHP and planning to use it. Following example will help you to install all other associated packages with MySQL.
Once installation is compete, you will need to run following commands to start the service automatically.
Regarding the security, you should do is running security script for MySQL: