IT issue

Hi. This is my first time using this forum and I'm hoping it would prove helpful for me. I was using my computer tonight when I accidentally went full-screen. I tried to escape and frantically pressed a bunch of random keys (which I don't remember). After that I realised that I had lost connection to the internet. When I clicked at the little globe thing on the task bar, it only showed airplane mode and the wifi option had disappeared! I have tried multiple things but I things but I reckon the problem is with the network adapters. The trouble-shooting revealed that 'windows did not a properly installed network adapter' Please help. Remember I'm not tech-savvy so an easy explanation would be appreciated.