HELP!!! WIRELESS TROUBLE

I just recently received my Dell laptop in the mail. Along with it was a Netgear wireless router. I am not computer savy. How do I get wireless internet? Do I need to get a modem? I don’t have a PC at home, this is my first computer. I also don’t have telephone service. But I do have cable. Should I get service with them? Where do I get a modem? Do I need one? Please help me?!