How To Impress A Boy At A Party?

By not trying to impress him.  If you are just being yourself, then you will at least be different to most of the people who are just trying to impress people at parties.  If he really does like you, then you can choose to take things further.  If he is more interested in people who are just trying to put on a show to impress, then he's probably not the type for you.

Well by wearing something nice and by dancing and the last thing you should do is go up to him and say hi , start a friendly conversation and maybe he'll like you.

Have the best dance moves ever! Take centre stage and dazzle him!