SSIDs and Physical security
It is always recommended to have separate networks. And in this case, the SSID (Network Name) of the guest network should be separate from the main network. It is best to enable a guest account on your router and assign a new SSID. You can leave this network open or password-protect it. Visitors will be locked out from accessing the main network’s devices like printers and other sensitive information.
Physical security.
In terms of a secure network, nothing is safer than having your guest network installed on a separate hardware. By having a few access points set up for the guest network, your guests could entirely be segregated from the main business network.