If this is your very first time at a rave party, play it safe. By 'safe' I do not mean you dress like a Plain Jane, but do not experiment to an extent that it proves to be uncomfortable! No matter what you wear and what you drink and what you eat, it is important you have a good time. Rave parties usually begin in the evenings and go on into the night and sometimes into the wee hours of the morning even. SO it is important what you wear is comfortable and something you can spend so many hours in!
Tops: The best thing to do would be a t-shirt. It is an unwritten code that boys come in black, and girls in flashy colors! So go babelicious! Wear bright colored tees - pink, green, yellow and hot favorites. If you are ok with a little bit of skin-show, you could opt for a halter neck or a t-backed tee. They look cool, casual and chic.
Bottoms: If you are wearing a fancy/stylish top, go for a plain bottom. Short tops can be teamed with boot-leg jeans. Loose over-sized tees can be teamed with hot-pants. Of course short tops and short bottoms go well together too.
Footwear: If you are gonna bear your long legs, you can opt for tie-ups. They look super sexy and are also super comfy to dance in. If you are wearing jeans or capris, you can go for sport shoe. And of course, if you opt for sport shoes, the laces HAVE TO be LED!
Accessories: Make sure your accessories don't get in your way. As long as you remember that, you are good to go!