how to fix a leaking ceiling after a storm, where to start?

i need real advice, how to fix a leaking ceiling in my small 2-story townhouse after last week's heavy rain. there's two brown spots above the living room light and water dripped twice yesterday, i put a bucket and tried caulk but it didnt stop. i bought some patch tape and that peeled off within a day. anyone know what to try next or what to ask a repair person for, im kinda lost and worried about mold.