You would need to have 768MB Ram and 20GB of disk space minimum for cPanel, and in the case of CentOS7 increase it to 1GB of ram. (https://documentation.cpanel.net/display/ALD/Installation+Guide+-+Hardware+Requirements) If you plan to host more than a handful of small low traffic sites, you will need more resources. You should also keep in mind the WHM backups do consume a large amount of disk space, if you plan to use them so you will need to watch your usage closely.