There are a few different ways: 1. There is a coach shuttle company called Cocord Coach Lines (https://concordcoachlines.com/stop/portland-maine/) that can take you from the airport to 5 minutes outside of Portland town centre. Cost can be found on the website, $30 one way or $50 return. Please note you will have to get a taxi from the coach company into town, normally around $10. 2. Rent a car from Boston Logan and drive up to Portland, ME. If you are planning to explore local towns around Portland we highly recommend renting a car. Public transport is limited outside of Portland.
We recommend staying in Portland. There are plenty of things to do and see in the town and it is close to the ferry terminal for the lobster bake luncheon on Friday.
If you are unsure where to look for flights, check out skyscanner. They compare prices with all different airlines to find the best deal. https://www.skyscanner.com/
Yes, UK citizens need a visa to travel to the USA or you will be denied entry. Please check the note on the travel tab for more information and the link to the ESTA website!