Running all the a/c units while on the move

[gbuss]

Ok. Here goes the first of what I predict will be many stupid questions. I've been reading the books and manuals that came with my coach, and going through the threads on here. I read several people talking about running the generator the whole time they are driving. Does the engine alternator not put out enough power to run all the a/c units while running down the road? Am I going to need to runn my generator any time I'm not plugged in to shore power to keep the fridge, freezer, and all that going? We leave on our maiden voyage in a week and I still don't feel like I know enough to stay out of trouble. Thanks in advance for any advice.