You'll have to enter a password. If you don't know what this is, check your manual for the default option. Usually, it’s something simple like admin or password. That’s why it is important to change the password to something less well-known.
Check your network settings first to see if you're running at "802.11n only." There's no reason to operate at the combined - and slower - 802.11g/n setting if you don't have to.
If you change to n-only and one of your gadgets gets kicked off the network, it's probably not n-compatible. Switch back to the mixed setting or upgrade the gadget.
With a dual-band router, you can effectively split your home wireless network in two. Have family members connect to the 2.4GHz band network for Web browsing and file downloads; reserve the 5GHz band network for gaming, video streaming and Internet voice/video calling.