can't connect old computer to AC3100 wirelessly

[midsouth]

Im running windows 8.1 64bit on an old envy sleekbook 6. I "can" connect to an unsecured wifi network but when i try to connect to my router, the error is "wifi doesn't have a valid ip configuration". i updated the driver. I have attempted to release and reset ipconfig. and i did something else..can't remember exactly what its called..something like tcp... in the I would like to try applying the settings manually, but do not know what IP address etc to use or where to find that info? I know just enough about computers to make myself crazy! Any advice would be truly appreciated.