TRANSPORTATION: Arriving in Gatwick Airport, you have several options for getting to Luton. You can take an express bus located at the airport terminal that will take you directly to Luton. You can take the train also located at the airport terminal which is much quicker because it avoids traffic but cost a few dollars more. You can also rent a car at one of the many car rental companies.
As is the case all over Europe, most people use public transportation due to scarcity of parking in central London and traffic congestion in most tourist sites.
With rental car companies available in abundance; unless you are familiar with driving on the left hand side of the road and proper use of roundabouts it is highly recommended that you use public transportation or taxies when needed.
The train runs from the airport (Gatwick) to Luton 24 hours a day. The cost is approximately 16.20 US and it is very fast and comfortable. The trains have storage areas built into each car to accommodate your luggage if you are traveling with bags etc., so that should not be a concern.
Many of the Hotels in Luton are located within walking distance of the train station so using the train for sightseeing or even transportation to the airport is very convenient.
For Sightseeing, if you stay in Luton for instance, you can take the train to central London; a ride of about 25 minutes. Once there, you have the option of selecting a variety of tour operators, buses and private cars to see the sights. Keep in mind that many of the sights are within walking distance of each other so a guide may not be necessary.
If you are interested in touring Eastern European Countries, you may want to consider the Euro Rail pass which allows you to travel as often as you like in any direction for a single price. The pass covers a time period such as a week or month etc., but is well worth the investment. The website is: https://www.eurail.com/en/get-inspired/everything-you-need-know-about-eurail