How do i get my Ps3 to obtain the IP address?

Wireless or Wired - if wireless you have to match the wireless settings of the PS3 with your home's internet router WiFi settings (same protocol and valid password).

If wired, you just plug it in and, assuming the route is working with other wired devices, that router should issue an IP to the PlayStation - but again you need to go into Settings of the PlayStation and make sure you know which setting it is currently using - wired or wireless, not both at the same time - and then make sure the WiFi settings, in particular, match that of the Internet Service Provider's Router wifi settings you have, which work with other wireless devices in your house (hint: The playstation will accept the same settings as all the other devices in your house which are wireless, so once you match them, it should work - unless the PlayStation itself has a hardware problem - that issue is beyond the scope of this forum to help you resolve).