why does my ip say unavailable and I can't connect to any Wi-Fi?

recently someone came out connected a box to our router and did who knows what when asked he said he's just checking the wire then another time they said they were gona upgrade us by changing the end of the wire ever since then I can't connect to Wi-Fi at all same goes for my cell phone I used to have an up address now I don't there has also been phone hammers around me

Was that just some random person, or someone from your provider? If it wasn't someone from your provider, have him come back and undo what he did.

For right now, forget the WiFi connection, then connect again (and you'll have to put the password in again).