The most basic thing anyone who wants to learn how to defend themself should do is at least learn how to block/counter/dodge haymakers and control distance. Also, keep your hands up. How many people get ko'd because they stood there not even facing their opponent while dude tees off on their head. How many cats get ko'd because of wild looping haymakers that could have been ducked/slipped. These basics alone will save you alot of embarrassment and injury.
Realest shyt ever right here. When I first took up MMA training, the head trainer even told us that the "comb the hair block"(where you bend your elbow and raise it to where your hand is by the back of your head as if your combing your hair, and your arm tight against your head/neck area, used to block hooks and lateral strikes) is what will save your ass in most street fight situations because it'll just be a matter of blocking haymakers until they gas out....then it's an easy lunch.