Hi lianlim,
You don't need to change or set the sourcetype nor the index name for the input just use the defaults.
Regarding the port; this will be a new port where you can access the dashboard - so you need to configure a free TCP port that will be accessible from your Squarespace hosted website. Once all the security concerns such a setup brings along are cleared and approved, you can access the dashboard like this:
<iframe src="https://<splunk_server_name>:<TheTCPPortYouConfigured>" seamless frameborder="no" scrolling="no" width="1200" height="2500" ></iframe>
cheers, MuS
... View more