Connect to a Wi-Fi network
From the Wi-Fi menu 
in the menu bar, choose a network. You might then be asked to enter the Wi-Fi network's password or agree to terms and conditions.
If you don't see the Wi-Fi menu in the menu bar
If you need help with the Wi-Fi password
If you can't join the Wi-Fi network
If your Mac doesn't connect to the internet after joining the Wi-Fi network
Connect using Personal Hotspot
With most carrier plans, you can share the cellular data connection of your iPhone or iPad (Wi-Fi + Cellular) with your Mac. Learn how to set up Personal Hotspot.
Connect using Ethernet
To use a wired connection to the internet, connect an Ethernet cable between your router or modem and the Ethernet port on your Mac. Some Mac models require an Ethernet adapter, such as the Belkin USB-C to Gigabit Ethernet Adapter or the Apple Thunderbolt to Gigabit Ethernet Adapter.