The PTO Today website has some great ideas and tool kits for organizing. I would avoid the father/daughter, mother/son name and go with something more generic like “family dance,” “sweeheart dance,” or “spring fling” etc. as the last thing you would want to do is make children with non-traditional families feel excluded.
Ours was around Valentine’s day so it was the Sweetheart Dance. When you have it will influence the decor - January would be wintery, February is Valentine’s day so red/white/pink, March you could do either early spring or maybe St. Patrick’s Day if that’s big in your area (call it the “Lucky to have you” dance), etc.
Part of planning is figuring out if it’s a fundraiser or just an event. If it’s just an event, you’ll want to keep ticket prices and costs low (charge just enough to cover costs), so I would get a DJ, simple decorations like colored table cloths, streamers, balloons and simple centerpieces. Have families donate desserts and buy some pre-packaged allergy-friendly desserts for kids who need those. If it’s early enough in the evening to overlap with dinner time, then you’ll have to offer real food. It can be included in the ticket price if that’s easier or be for sale separately. We usually stick with pizza to feed a crowd because it’s cheap and easy but sometimes you might get a local restaurant or caterer who can do something more interesting on a tight budget in exchange for advertising. If it starts later, at around 7 PM, then you can just do snack foods - chips, goldfish crackers, maybe some cheese/fruit/veggies trays, popcorn.
If it’s a fundraiser, you’ll need to price accordingly to make a profit and then include food (again, with the ticket priced to profit even with food) or sell it separately at a markup. For a fundraiser, it’s nice to also have games, a silent auction or raffle baskets as those can bring in money too.
I honestly wouldn’t serve alcohol at a school event with children. Our events are all booze-free unless they’re adult only. One of the sports teams in my town does a family party fundraiser with a cash bar and it’s a nightmare. Parents gather around the bar, toss a few back and seem to forget that they have children, who basically run around unsupervised. It’s so bad that I buy a ticket and don’t go. If this is the norm for your school though or people are really committed to having a bar, stick with beer and wine only. I don’t know if you’re in a public or private school but a public school will have all kinds of hoops to jump through for this. Even at a private school, in my town you would need a one-day liquor license, a trained bar tender, and would have to meet other requirements to serve even beer and wine.