To get to your Wi-Fi settings, you have to swipe down from your screen top. Then tap on the Wi-Fi icon for a few seconds. This should take you to your Wi-Fi settings page, and you should give your device your most preferred settings. You will also be able to see the list of available networks you can connect to. In other words, open your device's settings, click on the Network & Internet, and that should get you through it. The signal strength on the Wi-Fi icons indicates how strong the connected network signal is.