Many ways lead to Hamburg and its university and here is a short summary of your possibilities.
Flying into Hamburg can be a done even on a budget. Air Berlin is operating flights to Hamburg but you will have to take the underground to get into town. All major airlines fly into Hamburg as well so there is good change you will even get a direct flight.
Coming by train probably is the most conveniant option. Hamburg Dammtor is one of Hamburg main train stations and all ICE's stop here. From the station it's only a short walk to the conference venue as well as to all the hotels arround. There are direct connections from west, south and east.
Taking the car is definitely the worst option to get into Hamburg as well as to the venue. There aren't an many parking opportunities around the venue and the motorway to Hamburg has been under construction for a long time now. If you still insist on coming car you will have to check with your hotel about parking.