Most party stores that do rentals have everything you will need. The karaoke, the CDs , the microphone, all at a good price .
All you will need is a stage, (anything that will stand out and be known it's the stage, rug , curtain in that one spot(background) ) , some lighting (Christmas lights or anything that flashes on and off.)
For food you can keep it light since it's a karaoke party. (Fruits,Chips,pizza,cold sandwiches )
For drinks (juices, water, soda )
The idea is that all eyes are on the stage and the little "artist" when their on the spot light!!!
Tons of fun & very cheap!!