Wi-Fi problem on the laptop?

My laptop suddenly no longer connects to my Wi-Fi or he can't find it even though I'm definitely within range. I'm also connected to the cell phone myself.
He also shows under a red cross (see photo) what can I do?

Did you reset the router?

Looks like Wi-Fi is out. Tried to switch on?

Read! What's next to the red cross… VPN connection… Has nothing to do with Wi-Fi

What does VPN mean? And what do I do now?

How do I turn this on?

Depending on the laptop, there's either a switch on the housing or a key combination. What model do you have?

A laptop from Samsung R780

I can't tell you that by heart. Usually it is the FN key plus one of the F keys. (for me FN + F9). Should be a FTaste with an antenna symbol on it.