Oh and does walmart have those HDMI to DVI converter?

Some 22-24+" ones can do hdmi, but not all of them. 

You can buy a cable in any decent computer store.

http://www.newegg.com/Product/Product.aspx?Item=N82E16812816008&cm_re=dvi_hdmi-_-12-816-008-_-Product 10$ on newegg you wont even need an hdmi

Oh my PC monitor is a acer LCD 15.6 wide(inches)

Yeah so no hdmi, just buy a hdmi-dvi cable. Make sure you have a dvi input in the back, or you'll also need a dvi-vga adapter to plug it in.

I found one on the walmart site so i guess Ill order it from there its priced at $12.88 its not sold in store,another thing will the letters look small like they do on the SDTV or will they look at least readable like on HDTV

Oh and a little more info on the audio please

hdmi to vga cable or hdmi to hdmi cable or hdmi to dvi cable if your monitor has any of those inputs. there are also other ways involving cables

HDMI to VGA cable if your monitor is old, HDMI to DVI cable if it's within the last few or so years. They did use to sell those at Walmart although you could probably find them cheaper online.

You'll have to go digital audio out if your display doesn't have any sort of USB/audio input/outputs (typical for bare bones monitors). Unfortunately, you'll need to get a digital audio cable Y splitter to RCA stereo plugs or a digital audio to 1/8" mini-jack converter to plug in headphones or computer speakers. It's a workaround, but it can be done.

You also might be able to get a USB headset to work with the PS3, but I own one and it does not work (needs driver).