You can learn how to stop your device from automatically connecting to a wi-fi network.
Step 1: Go to the settings app on your phone.
The settings icon on most devices is gray.
Step 2: There is a Wireless & Networks heading.
The settings section will be at the top of the menu.You might have to tap a tab at the top of your screen depending on your device model.
Step 3: Under Wireless and Networks, you can tap on the wi-fi.
Step 4: The switch should be on position.
You can find it in the upper-right corner of the screen.You can see a list of all the available networks around you.
Step 5: Hold onto the network you want to forget.
The pop-up window will have network options.You might need to tap on the network instead of holding it.
Step 6: Go to Forget in the pop-up.
Your device will stop connecting to the network.If you want to connect to the same network again in the future, you will need to enter a security password.