TL;Dr Bumped in the girl that loves nextdoor in the elevator. Had a fun convo. But I didn't get her name or anything, don't know how to proceed.

Title is literal. Need help with next steps

Cute girl on the floor of my apt. Bumped in to her on the way down in the elevator. Surprisingly that wasn't the awkward part. She had some bag she was holding and I could smell the bakery goodies lol. So here is the run down of the convo:

Me: "do you have cookies in there? It smells good"

Her: "A cake actually, I thought I burned it! So it's good that it smells alright still"

Me: "yeah it smells really good. Cake for an occassion?"

Her: "my birthday actually"

Me: "happy birthday! making yourself a cake? Aw, you should get friends" (technically that's a neg, I believe. Though I don't it's that bad of one, I know negs are not accepted as much as before in the whole seduction book of tricks)

Her: "its actually my bday on Monday. haha I'm actually going to my friends to dress it up"

Me: "oh cool. So you are on my floor? Which end?"

Her: "I'm actually in apartment 748, but we aren't the loud ones!" (I think she was referring to this one really loud girl who everyone on our floor knows when she is getting fucked. It's really funny actually. But I didn't realize that's who she might be talking Bout till later)

Me: "haha we're probably loud ones. Anyways I'll come say hi"

Her: "talk to you later!

And off we went seperate ways. But get this, we came back at the same time and I ran in to her again on the way up the elevator!

Me: "hey it's you again"

Her: "hey it's you"

Me: "how was dressing up your cake? What kind wasn it?

Her: "just basic chocolate. Not too in to fancy cakes"

Me: "do you like cheese cake"

Her: "I love cheesecake!"

Me: "ever been to the cheesecake factory"

Her: "omg yes! I love that place. Do you mean the ones that's over in city "

Me "I used to live near there so I always went there"

At doors now.

Her: "thats awesome. We'll talk soon"

Me: see ya later!

I'm an idiot because I didn't get her name or anything. I just freeze up in situations like this because Im hyper aware of myself. I know I'm trying make this.more than just a passing interaction, but it also makes me overthink it and I forget basic shit like "hey Im puanerrd by the way, nice to meet you" She's gone for the weekend, and it's her bday tomorrow.

My question to you guys is, how would you go about saving/escalating/something this breif interaction? I wanna go just knock on her door and say hi. But if she has roommates that answer I have no idea what to say to them cuz I don't even know her name lol.

Edit: added a purpose of post in first line, and a TL;Dr