I’m so stupid. What should I do

I’m actually stressing out right now. I’m a female college student living alone. Tonight at around 3am there’s a man came knocking on my door asking to use the toilet and the lighter. I said no, and he’s like okay and walked away. I guess he was walking to other doors cuz I heard his voice roaming “Hello”

Reason why at that time I didn’t just ignore him was because I was studying in the living room (with light on). And the blind at my living room window have like small gaps on the side so if someone actually look I guess they can still see me sitting there

Monday morning I’ll ask the complex manager to check on the camera. I don’t know if that’s all I could do. What will you do in this situation? I’m hoping that he’s just someone needing help for real; but what if he’s around to see who’s living alone?

Am I overthinking? I’m hoping that he just came because he see my lights are on. But there’s a gas station like 5 mins away from my area. I saw a car leaving later and at this time I’m assuming that was his car — If he has a car, why don’t he just go there? Why didn’t I think of that

idk I’m really scare. I dont have family here, it’s just me, I feel like I’m so stupid for answering the door. I don’t even have a car so every day I’ll have to walk to the bus station, I don’t go out when it’s dark

I’m so stupid. Sorry for my broken English, I’m not a native speaker

Update:

I called the nonemergency line. They said since he left almost an hour ago and he didn’t commit any crime so they can’t really do anything. But they told me if he come back please call them when he’s still there

This is the answer I expected too, because there was nothing really happened. And yes I should have called when he seems to still be there. At that time I was afraid that I would get an innocent in trouble. I’ve never been in this situation before so yes I’m dumb.

But I pray that this is the once in a while thing and there’s no real intention from this (please 🙏). Thank you for all the advice and I’ll do so if it ever happen again!