To set off: To start on a journey. E.g.We need to wake up at 6 am because we need to set off by 6.30 am.
To drop somebody off: To let someone or a group out of a vehicle at a particular place; to deliver someone or something some place. E.g.Don't worry if you are running late, I can drop you off at the airport.
To pull over (a vehicle): A vehicle moves to the side of the road and stops. E.g. Just pull over by the petrol station, and I'll run in and buy us some chocolate.