Why not contact a few hairdressers and ask if they can do a 1:1 lesson with you to style/curl your hair? You might want to find someone who specialises in hair up/Prom styling as they’ll be very experienced at dealing with lots of different hair types.
It’s not just about using the right tool and temperature (don’t burn the hair). Depending on your hair type, you need to apply the right products on your hair to ensure that the curl/wave stays in for a few hours and doesn’t drop out within 30 minutes. There are hundreds of products on the market for styling hair and an experienced hairdresser will be able to recommend their tried and trusted products to save you wasting money buying a dozen different bottles when you might be better off with just one or two specific items.
In the meantime, you could try sectioning your head into 4 quarters or more smaller sections, and plaiting your hair after it’s been washed and a styling product applied. Leave it to completely dry for several hours. Remove the plait when the hair is bone dry, not damp and run your fingers through it to separate the hair into soft waves.