Boston Logan International Airport is the large airport closet to the cape. Brewster is 1 hour and 30 mins from Logan Airport. Once arriving at Logan, a rental car or a bus ticket will be needed to get to the cape.
The Peter Pan bus makes trips from Logan to the Cape. To book a ticket please see the website below.
https://peterpanbus.com/destinations/cape-cod/
Once you arrive on the Cape, Ubers/Lyfts are readily available to explore the Cape during your trip.