Keyboard behaving weirdly after water spill

Plug in an external monitor, keyboard & mouse. Then Start the system up close the lid and use the Plugged in stuff. Does the system work correctly? If it does then you need a new keyboard

Without the full setup as I’ve outlined your test won’t work.

@julie22286 - There are two directions you can go to fix this fully. They both require taking the system apart. One a-bit more. Consider the work involved.

The bigger joy does use a cheaper part MacBook Air 11" (Mid 2011-Early 2015) Keyboard Whereas the second option uses a more expensive assembly but is a-bit less work MacBook Air 11" (Mid 2013-Early 2015) Upper Case

But you need to see how much damage the spill caused before you order the part as that too is the Important question here, this is the guide you need to follow MacBook Air 11" Early 2014 Upper Case Replacement then for the keyboard carefully digging the keyboard out of the case.

Given the systems age you may also need a new battery MacBook Air 11" (Mid 2011-Early 2015) Battery to check install this gem of an App CoconutBattery post a snapshot of the apps main window here so we can see it.

So while none of this is overly hard the cost are getting up there. You may want to look at acquiring a newer used system as being the better long term solution. I would look at a 2018/19 MacBook Air.