"Karate ni sente nashi" ....Guchi Funakoshi It means, in karate there is no first strike. It could be interpreted literally for beginners but more advance usage is that, do not cause trouble, if trouble finds you and you are in a situation where attack by your opponent is imminent then attack pre-emptively and utterly and quickly to end the situation.
"Knowing is not enough we must apply. Willing is not enough. We must do"... Bruce Lee
From the movie The Karate Kid
Mr Miyagi's advice to Daniel San seem quite legit:-
Punch! Drive a punch! Not just arm, whole body! Hip, leg, drive a punch! Make "kiai." Kiai! Give you power. Now, drive punch. Better learn balance. Balance is key. Balance good, karate good. Everything good. Balance bad, better pack up, go home.