The servers can be managed individually (https://www.cisco.com/c/en/us/td/docs/unified_computing/ucs/c/hw/C240M4/install/C240M4/install.html#46057)
You will want to reset the CIMC, and set an IP address on it so you can use the vKVM, virtual media, etc using direct web interface to the CIMC IP address you assign.
In the CIMC, there is bios section for boot order, so you will want to create a boot order for what ever type device you are planning on booting to. The HX240m4's originally were shipped with pair of 64GB SD cards in a mirror/sync.
As is the case with host HCI solutions, the SAS adapter is an HBA, and not a raid controller, so that means your disks are all in jbod mode.
That is not ideal for a stand alone server, as ESXi doesn't do software raid, etc.
The CIMC will have a storage config area, but there is nothing to configure as all disks are jbod without an actual raid controller.
You could setup a linux type install, that will do software/OS level raid.
Kirk...