Hi Alana,
Welcome to the arduino world. imho the wave shield is one of the better/cheaper solutions.
you need to have a wifi shield to send a command to a PC to do the sound /light you want. On the PC you embed a webserver with some forms to choose sound and light and the Arduino just fills in these forms. Example code can be googled for and if it doesn't work come to the forum for assistance.
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https://www.sparkfun.com/products/9954 -
other suppliers exist