1. If the wifi is not working. Usually a hard reset will do the trick. Unplug both the modem and router (pictured below) from their power outlets. Wait for 2 minutes. Plug the Modem in first and wait 2 minutes. Finally plug in the router. 

2. If you still do not have internet, please call charter spectrum customer service at 1-833-694-9259. They will usually be able to reset the service on their end or let you know if there is an outtage in the area.
The number connected to the account is 314-452-9992