Ok. So I am going to my senior prom in about a month. After prom, we will probably go to a party. What can I say/do to make her want to go upstairs? I don't have much game so I need your guy's help. Thanks

Many things come into whether this would be a horrible idea or not.

1 Are you guys just friends?
2 How long have you guys known each other?
3 Does she give you any IOI's?

1) Not quite sure. We used to work together about 3 months back. Then I got fired. She isn't from my city. She is from the next one over. We have never really hung out but we have talked a bit...
2) I worked with her for like 6 months.
3) Not sure what IOI means but I am guessing it means something like signs of interest. I made a tweet about needing a prom date and she replied saying, take me!. I was kind of surprised. I asked if she was kidding and she said she wasn't so now I am taking her.

But I feel anything can happen on prom night. Especially if we have been drinking.(Just saying).

You're looking for some sort of line that is going to have her want to hook up. I don't know the line, neither does anyone else in the world. She's not an on and off switch, more like a volume knob. You need to work her the entire night instead of just a few minutes.

Read up about kino escalation. Make sure you are looking fresh, don't try too hard to get with her. It's like the opposite of tug of war. The more you push the more she will pull in, and vise versa.

I think it's less of a matter of a specific line but more of a matter of how you behave the whole night.

From the get go, you should be giving her clues your interested. As others have mentioned you need kino, you should also complement her on how she looks and say how attracted you are to her (without specifically saying it).

Eventually your going to just need to make a move and say something like "I want to show you something" and leave with her.