Hi Robyn,
My family positively loves
Bay Lake Tower at Disney's Contemporary Resort. The theme is so very sleek and modern, and to be able to walk to Magic Kingdom is wonderful! Be sure to take some time to swim at Bay Cove Pool - it is one of my favorite pools at Walt Disney World.
There is a parking lot directly in front of Bay Lake Tower. When you arrive, simply let the cast member at the security booth know that you are checking in to Bay Lake Tower, and he or she will direct you to the correct parking lot. There is now a check-in desk located in the lobby of Bay Lake Tower. There are also cast members in the lobby of Bay Lake Tower who can help you to get Bell Services to assist you with your luggage.
As to concierge service, there is not a concierge level at Bay Lake Tower. However, I believe that you are asking more about the availability of a concierge cast member in the lobby of Bay Lake Tower to assist you with items such as making Dining Reservations. There are cast members in the lobby of Bay Lake Tower who can help with these types of requests.
Please note that if you are arriving extremely late at night or extremely early in the morning, the services I mentioned above may not be open in Bay Lake Tower; however, you would simply need to go to Disney's Contemporary Resort lobby and they would be able to help you with any of the above.
I would like to thank my wonderful fellow Disney Parks Moms Panelist Jacqui for her help with this question. Have a great time planning your trip, Robyn, and please do not hesitate to ask if you have any further questions!