Once you have your Write Key, navigate to your Company Settings in the management interface and fill in the "Segment Write Key" field with your Write Key. Don't forget to hit save.
You can then enable any integrations on the source in Segment. The setup for each integration differs, so we are unable to provide specific help for a particular integration, but Segment's Support can help guide you.
We automatically send all tracking script events to Segment, as well as all of our realtime webhook notifications. We also automatically send an "identify" call for every student. To find out what each event contains, Segment automatically builds a Schema of all events which you can access in the source you created. Simply perform the events in TI and they will automatically appear in the Schema after a short period of time. From there you will be able to view the properties on each event.