@PankajGIC Thank you for the explanation. Regarding the first issue, Google Analytics has two types of fields, Dimensions and Metrics, and the documentation below shows which fields are which type. It is a requirement of the Google Analytics API that at least one metric be specified in a query, and since you are only selecting Region (which is a dimension), this error is being thrown. To resolve this, you will first need to select one of the fields that is marked as a metric, such as UserEngagementDuration.
https://cdn.cdata.com/help/DAJ/tableau/pg_GoogleAnalytics4table-acquisitions.htm
Regarding the second issue, 'jdbc:googleanalytics:' is not able to authenticate to Google Analytics because it is not a valid connection string for a Tableau driver, as this is the first part of a JDBC driver's connection string. There are two ways to resolve this. The first would be to run the cdata.tableau.googleanalytics.jar connection string builder, set the properties as described below, and press Test Connection to generate a connection string. The connection string should look similar to: Schema=GoogleAnalytics4;AuthScheme=OAuth;InitiateOAuth=GETANDREFRESH;
https://cdn.cdata.com/help/DAJ/tableau/pg_connectiontableau.htm#google-analytics-4
The second would be to leave the Connection String property blank, as this is optional, and just set the properties as described in the link above directly on the 'Google Analytics by CData' interface.