Welcome to TPG Community,
You can private message to me your customer ID, username, service address or mobile number so i can check status here.please tell me which modem are you using as well.
If any issue let me know which operating system you have for your computer so i can advised you accordinly. some desktop doen't have wireless adaptor so that might be reason as well for not detecting wireless network.
Turing on /off wireless from router,see below link
How to Connect to Your Wi-Fi network, see below link.