HTC Droid Eris — Droid Eris Problem

I just recently bought a HTC Droid Eris. And, it's a Verizon phone...but, I have it on a Page Plus plan. My question is...why doesn't some apps work. For example, YouTube, Facebook, Market or even the Internet. When I click on the Market app...it doesn't load. I'm connected to WiFi. I click on YouTube and it says something about check my internet connection. But, my connection is WiFi. Help, please!!!

If you are connected to a wifi but no data received, check if the wifi you are connecting to has an internet connection and although you might be connected to the wifi, it has limited connectivity (no internet) ask for help from the administrator of the wifi network. Also try to connect to other wifi hotspot to see if it is the same with other wifi networks. Try also to set-up again your wifi connection and be sure to provide the correct settings and passsword, check this link for further guide on how to do it http://www.techyv.com/questions/internet-mobile-connection-problem-android