How do I secure my internet connection(Block Access)?

I just had this problem last night when I noticed there was a steady yellow light on my modem for the wireless connection. I thought this was odd since it usually isn't lit, so I called my internet provider & they had me type: 192.168.1.254 in the address bar, then go to Home Network, Wireless Settings, Identify Network & then change the "Network Name". Next where it says Wireless Security uncheck the circle that says: use default encryption key & check the circle that says: use custom p phrase. Enter a 10 digit number & SAVE. Once I hit save, the yellow light immediately went off. I hope this helps.