@Susic Info from owners manual page 97.
Wi-Fi
You can connect your device to a Wi-Fi network to access the Internet without using your mobile data.
1. From Settings, tap Connections > Wi-Fi, and then tap scan for available networks.
2. Tap a network, and enter a password if required.
I don't know why it says tap a network. Tap your Network
That should also say enter your router password.
3. Tap Connect.
If this doesn't work page 98 in the owners manual has more steps to try.