Don't worry, the only stupid question is the one that isn't asked.
If your PC works when you connect the network cable to the PCs NIC, so will the router. Once you physically connect the modem to the router you will get internet access through wireless, but you have to configure the modem first.
To do that, first connect the router to the PC physically, set up the connection, then connect the router to the modem.
AFAIK the modem does not require to be configured unless it is locked to your PCs MAC address, and I'm not sure that's how they do it. At least, when I had a modem it could connect to any PC configured with the right IP settings, and logically it would allow a router too.