Explanation
https://docs.splunk.com/Documentation/Splunk/8.0.1/Forwarding/Aboutforwardingandreceivingdata
https://docs.splunk.com/Documentation/Forwarder/8.1.1/Forwarder/Configureforwardingwithoutputs.conf#:~:tex

Explanation
Immediately after installation, a universal forwarder will start generating internal Splunk logs that contain information about its own operation, such as configuration changes, data inputs, and forwarding activities1. These logs are stored in the $SPLUNK_HOME/var/log/splunk directory on the universal forwarder machine1. The universal forwarder will not automatically detect any indexers in its subnet and begin routing data, as it needs to be configured with the IP address and port number of the indexer or the deployment server2. The universal forwarder will not begin reading local files on its server, as it needs to be configured with the data inputs that specify which files or directories to monitor2. The universal forwarder will not send an email to the operator that the installation process has completed, as this is not a default behavior of the universal forwarder and would require additional configuration3.

Explanation
https://docs.splunk.com/Documentation/Splunk/7.3.0/Admin/Wheretofindtheconfigurationfiles
"To determine the order of directories for evaluating configuration file precendence, Splunk software considers each file's context. Configuration files operate in either a global context or in the context of the current app and user"