Press and hold the Windows key.
Press the space bar. That will show the current keyboard setting and any others which are installed. (The one highlighted in blue is the current one).
Repeatedly pressing the space bar toggles through all of the available options. (You might have lots or just the UK and US ones, depending on how Windows is set up on your laptop).
Once you've got the UK setting highlighted in blue everything should be back to normal.
If you want to make sure that it can't happen again, remove the US keyboard (and any others that you'll never use, if there are any):
https://www.isunshare.com/windows-10/2-ways-to-remove-keyboard-in-windows-10.html