Names can be arbitrary alphanumeric strings or something more personalized — it’s entirely up to you. 

A valid workerName must match the following regular expression "^[-a-zA-Z0-9_@+:]+$" (i.e. don't use character types that are not listed in the ""). If a workerName is not provided at all or doesn't match the regexp, the hash rate is accounted to the automatic worker called “[auto]”.

You can use more miners with the same worker credentials. However, we recommend that you connect each mining device to a separate workerName for efficient monitoring.

As for the password field, you can ignore it completely. It is a legacy Stratum protocol parameter that has no use nowadays.