An airport limo of course has the impressive benefit of being very large and this of course means that you are going to be able to fit most things into it. However you should still make sure to alert the limo service if you are hoping to fit in a wheelchair for instance or if you have an unusually large amount of luggage with you. Let your limo service know of any special requirements well in advance and they will be able to ensure that you have enough room while at the same time bringing additional facilities such as ramps etc.
Other than that you will have very little admin to do yourself and this is part of the joy of limo services – it is no where near as stressful for instance as looking up bus and train times online and organizing a taxi to get there while trying to ensure you don’t miss any connections. All that’s then left regarding your limo service is to make sure you are comfortable and entertained – so pack things to read and listen to, and make sure you have food and cushions to increase your comfort.