Can someone me start an introduction about animal testing? i already have a hook but i don't know how to start from there.

You could back that up with research about terrible effects of testing physcially.

Then you could research mental health and peoples views morally about it.

Against-
-have a rhetorical question
-ust strong words to invoke deep emotions
-make it sound very extreme and sad( example- these animals suffer inhumanely every day and its up to us to stop this)
-talk about how animals have the same right to live freely as humans

for-
--question is they would want to be tested on then say "probably no right?"
-show that the pros outweigh the cons(explain how its  more positive than to test on humans)
-mention humans being the superior species