There are several ways to do something like that. Exactly how that happens depends on whether all the information is stored in the same CloudDB tag or each user's information is stored under individual Tags.
One way might be doing something like the attached example; another way might be by doing something like illustrated in this tutorial Social Distancing ... a CloudDB / Location Marker Tutorial . Exactly what is needed depends on how the information from each user is provided (by an administrator, by a LocationSensor on a user's device, from a GoogleSpreadsheet etc. You need to decide this.
Example:
The example (which shows how to work with Map, not how to implement using the CloudDB) might help you decide a method.
simpleMultiMarkers.aia (5.8 KB).
It shows three Markers. I am aware of a developer who used over 25 runtime markers successfully doing something similar; 50 might work. Start small.
Load the aia; then press #1, then 2 etc. to see how this simple app works.
Only admins? Then suitable code has to be written. A developer could modify data using Blocks alone or using a Googlespreadsheet - this can get very complicated.
Experiment and see what you can do.