I have known so many people who get bulldogs thinking they are very laid back, but it is the complete opposite lol. The Bulldogs that I know are very hyper, and playful, rambunctious. Now I haven't seen them become human aggressive very often but I have seen them become dog aggressive.. My suggestion is obedience training with a professional. Its worth it, it doesn't cost to much either, around $140 for 5-7 weeks of training... They will help you with behaviour and how to handle situations when the dog is about to react with dominance... I wish you much luck.. He sounds like a beautiful dog, we need pics ,,

Take care.