how do I add a laptop to my wireless. I don't know what my password is for wireless
You have to log into your wiress router (assuming it's the same device) and somewhere under the Wireless settings will be Security. There you will see the options. If you have Zero devices connected wireless now, it's easiest to just change the password to whatever you want.
Connect an ethernet cable between the laptop and the wireless router. Run CMD.exe and type in "ipconfig /all", then make a note of the Ethernet Adapter Local Area Connection - Default Gateway ip address. That IP is the address you need to type into your internet browser to log into the wireless router.