- Open System Preferences from the Apple menu and click on Network
- Click the Wi-Fi network
- Now click on Advanced and then choose the Wi-Fi tab
- Click on the wireless network you want to connect to primarily and drag it to the top of the list, arrange the other networks by priority
- Click OK to save the changes and close out of System Preferences
Whatever the topmost wi-fi network is will be the first to be joined, assuming it’s available. If the topmost network isn’t available the next one down will become the preferred network, and so on.