2 Wi-Fi networks on a router, how can I delete one of them?

I have a big problem. Since I restored my router, I have had two Wi-Fi networks since then. Now I would like to delete one of them, since I don't need two (Fritzbox). In addition, the Internet has not been able to be used on the laptop since then.

Log into the web interface of your Fritz Box (fritz.box) and see what networks are displayed there.

I guess that the guest network is activated, you can simply deactivate it.

The 5 GHz network is probably active.

Or the 5ghz network

Just use Wi-Fi Mesh with the Fritzbox then you have a network that includes all devices with band steering and access point steering

You have 2.4 GHz once and 5 GHz once.

You can simply remove one of them in the FritzBox if you don't need it.

And what does that bring without a corresponding repeater, of which nothing was mentioned?