Welcome to Auth0 Community!
As long as the Welcome email template is enabled, there should be a Welcome email sent automatically even when you create users with the Management API. We do not have a way to send a password reset email automatically upon user creation in the same way, though it can be done though the /dbconnections/change_password endpoint of the Authentication API right after user creation:
https://auth0.com/docs/api/authentication#change-password
This endpoint will send an email with a password reset link rather than the
POST/api/v2/tickets/password-change endpoint which will only return a password reset link.