How Do I Free Up Disk Space to Install Centos 8?

I just purchased a Linux VPS thinking it came with Centos 8 but to my horror it does not appear to be installed. If I am to make use of this server I need cPanel or I can't use it all because my only experience with Linux servers is with cPanel. When I try to install Centos it says that the hard drive has zero free bytes. Is this a permissions problem or is the disk corrupt?