Depending on the type of Journey you're setting up - you probably want to collect different information in the beginning.

For a new hire, the first workday is important, while the last workday is the important information during offboarding.

Under Settings -> Attributes, you can now add the attributes you want to use in your Journeys:

Then when you're creating setting up a Journey, you can add the attributes you want to collect in the beginning of the Journey: