[HELP] Modifying particle

Hi there, I am an absolute beginner on this software so I’ll apologize for any misuse of vocabulary in advance. I am trying to make a particle emitter of a smoke explosion change in two ways : I wish my explosion was much smaller, in its entirety, and much slower, but following the cascade documentation doesn’t seem to bring me to where I want to go. Could anyone explain me really quickly how to globally change these two parameters : the scale of the explosion , the speed of the explosion.
Thank you very much in advance.