Connect to a wireless network
Open the system menu from the right side of the top bar.
Select
Wi-Fi. The Wi-Fi section of the menu will expand. 
Click the name of the network you want.
If the name of the network is not shown, scroll down the list. If you still do not see the network, you may be out of range, or the network might be hidden.
If the network is protected by a password (encryption key), enter the password when prompted and click Connect.
If you do not know the key, it may be written on the underside of the wireless router or base station, or in its instruction manual, or you may have to ask the person who administers the wireless network.
The network icon will change appearance as the computer attempts to connect to the network.
If the connection is successful, the icon will change to a dot with several curved bars above it (
). More bars indicate a stronger connection to the network. Fewer bars mean the connection is weaker and might not be very reliable. 
Connect to a hidden wireless network
Open the system menu from the right side of the top bar.
Select the arrow of Wi-Fi. The Wi-Fi section of the menu will expand.
Click All Networks.
Press the menu button in the top-right corner of the window and select Connect to Hidden Network….
In the window that appears, select a previously-connected hidden network using the Connection drop-down list, or New for a new one.
For a new connection, type the network name and choose the type of wireless security from the Wi-Fi security drop-down list.
Enter the password or other security details.
Click Connect.