Any advice on how to manage this trip without a car? Is there a good bus? I see a long train ride.
Thanks.
Just a quick check on train line shows about 3 1/2 hours by train. I didn't check the details re changes or type of train. Have you checked the SNCF site?
Neither train line or SNCF will tell you how to reach the airport as it has no train station.
You need to go to Beauvais Station then a citybus run by Corolis - route 6, or early and late route 601.
If you go via Paris you have to change stations to Nord for a TER, but several times a day there is a short cut on TER trains avoiding Paris, changing at Abancourt.
If your timings are right the not Paris route is a useful alternative, especially if travelling with luggage.
It should be about 2 hours + the wait time for a bus+ 15 minutes on the bus on that route.