Where do I enter PPP user name and PPP password?

Where do I enter PPP User Name and PPP Password when installing a new modem? I followed directions for installation but a dialog box asking for those items didn't come up.

I reset the Wi-Fi on the System Preference > Network Pane after turning off all my wireless devices, MBP, iPad, iPhone, Canon MG5320 printer/scanner, and HP LaserJet Professional P2606N (this printer is connected via ethernet to AirPort Extreme).

I did this because of the following message:

Another device on the network is using your computer’s IP address (192.168.0.1)

Following directions I unplugged the PK5001Z Modem, plugged it back on, and then turned on each wireless device, one at a time so that unique IP addresses would be created for each one. This worked, but now I'm trying to get our Smart HD Samsung TV to connect to the internet.

Setting up the IP Internet settings, we are using the Network Name and entering its IP address manually and also having the setup find the IP address automatically. It connected to the modem but couldn't complete the connection to the internet.. Also use a Guest Network, but that didn't work either.

Is the PPP User Name and PPP Password still necessary? It was given to me by our service provider and was original in 2012.

Bonnie