You can enable 2.4 GHz Guest Wi-Fi network and disable 2.4 GHz Wi-Fi on your main network.  Keep in the devices on the main network cannot communicate with the devices on the Guest network.

If you want them to talk to each other, make sure the 2.4 GHz and 5 GHz SSID names are different and you can connect the home security to the main 2.4 GHz SSID and other devices to main 5GHz SSID.

Guest Wi-Fi Network Setup

https://arris.my.salesforce-sites.com/consumers/articles/General_FAQs/G34-G36-Customize-Guest-Wi-Fi-Network

Primary Wi-Fi Network Setup

https://arris.my.salesforce-sites.com/consumers/articles/General_FAQs/G34-G36-Changing-the-Wi-Fi-Name-and-Password

Click the Disable when you get to this screen.