@robinthebank101 Imparfait is for actions that happen frequently (every day she went to school = tous les jours elle allait à l'école), actions that aren't finished (she was drawing [as opposed to she drew, because then she's finished drawing. Do you get what I'm saying?]= Elle dessinait), background actions (she was drawing when someone knocked on the door = elle dessinait quand quelqu'un toqua à la porte).
On the contrary, passé composé is for actions that are unusual (that day he ran to the hospital in a panic = ce jour-là il courut jusqu'à l'hôpital en panique) finished actions (she drew a mouse = Elle dessina une souris) and foreground actions (same example as for the background actions but just look at the other verb).
I hope this helps!