Securing your wireless network is something everyone should do. It keeps leeching neighbors from bogging down your connection. And it helps keep attackers and criminals off of your network.
Every wireless router has encryption settings. You can access your router through your browser. But you need to know the router's IP address to do it. You'll also need to connect your router and computer physically. That requires an Ethernet cable.
I advise keeping all of your manuals for situations just like this. You never know when you'll need to reference them. However, you're not out of luck. It's actually pretty easy to find your router's IP address.
Router manufacturers usually have a default IP address. It is the same for most of their models. Most Linksys routers use 192.168.1.1.
Open a browser and enter http:/ /192.168.1.1 in the address bar. Hopefully, this will take you to the router's log-in screen.
Other manufacturers also have default IP addresses. D-Link and Netgear often use 192.168.0.1. And Belkin routers regularly have 192.168.2.1.
But there is no guarantee these defaults will work for your router. Every manufacturer has routers that don't use the default.
The manual will tell you the default IP address. Luckily for you, it's easy to get a new manual. Manufacturers put them online. You can just download a copy.