0. Installation and Main menu

Install using HACS

OR

If you can't find the integration, add this repository to HACS, then:
HACS > Integrations > GTFS2

Add in Integrations

From the HA menu: Settings > Devices & Services > Integrations

You will find the main menu:

With the very first setup, you will have to commence adding a data source (link)

If you already have a data source installed then you can use that data source to:

• add a sensor for the schedule between two stops: (link)
• add sensors for stops around a pre-defined 'person' (link)