Go to System Preferences > Keyboard > Input Sources
Select the Layout you want.
Go to System Preferences > Language & Region > Keyboard Preferences... > Input Sources
Select the Layout you want.
If you don't see the one you want, press '+', bottom left corner.
I have tried the above also which has not fixed this problem and I have also inserted a USB keyboard which works but still types the wrong symbols and letters. If I press caps lock on the external keyboard, my internal caps lock light comes on.
Have you spilled any liquids on the keyboard?
It looks like the option key is stuck on your laptop keyboard. Try to lift both the option keys up a bit and see if you can type whilst doing that.
Try an external keyboard. If it works ok, the internal one probably needs repair.
What gets displayed when you type asdf?
MacBook keyboard typing symbols instead of letters