Q: after Mavericks upgrade, can't connect to internet

We upgraded our MacBook Pro to Mavericks, last night.  Immediately afterwards, the wifi stopped connecting to the internet.  It will allow us to join our WPA Personal network, but says it has a self-assigned IP address.  I can't figure out why it would have connected just fine before the upgrade, but won't, now.  I feel like it's probably just a setting we need to click, but have been at this for over 2 hours, now, and can't sem to find the right box to click.

Thanks,

Elizabeth