Hey Andy, you have a few options with this outfit, here is my assessment.
Firstly, choose your necklace. It should be a pendant on a change. Shiny silver is a classic option, but it is also very popular.
Gold slightly chunky pendant will have a great impact and be a bit bold. You could accompany this with a simple gold bracelet/chain.
The third option is somthing that is not as shiny. Maybe a dull gold or metalic colour, or something with a bit of a tribal-feel. This might have the tiniest hint of colour. This is hard but if you pick and you will need earrings that match really well.
Possibly you could do pearls if you have a nice set, it's always a good safe option, but might be a bit more predictable.
The 'young' fun option is to pick a bright colour of stone or bead. You could make the most of your age and wear jewellery nobody else there will be able to get away with.
Definitely get a simple black satin clutch. Not too big, something that matches the shine of your dress. Your heels should be satin to match your clutch, maybe peep-toe but with not much other decoration. I'd say no to gloves. You should french your nails, definitely the best classy look. To match this your makeup should be mostly neutrals and pale pinks. Really delicate colours. However if you pick a very striking colour pendant than go all out and match your nails to that.
Hair in an updo obviously, make sure your keep some wispy bits around your face. Keep your earrings really small, prefferably studs, especially if your necklace is the feature.
