If you only have one host you don't have a cluster. If you don't have a cluster you don't have DRS. If all that's supposed to be correct, you can just disregard that warning.
Why you need to start Pre-Check remediation? Do you want to patch or install an update from the vSphere Update Manager?
Are you familiar with the tasks of each of the vSphere suite's components?
Do you see this error when you directly connected to the ESXi host or on the vCenter web console?Please mark my comment as the Correct Answer if this solution resolved your problem