Why can I not access internet?
Restart your device.
Open your Settings app and tap Network & internet or Connections. Depending on your device, these options may be different. Turn Wi-Fi off and mobile data on, and check if there's a difference. If not, turn mobile data off and Wi-Fi on and check again.
Why my Wi-Fi has no access to internet?
It could be due to broken cables, service disruptions, or just about anything else that's not within your control. That said, it's important to know if the problem lies with your Internet provider. For this, check if the “Internet” light on the modem is working. Ideally, the power and DSL lights should be turned on.