Sorry, I have to address this now:
Aircraft do not takeoff and land from opposite sides of the same runway, they both use the same side.
This is to avoid what just happened, you cleared me AND the other Spitfire for takeoff while a landing aircraft was barreling towards us
Another thing, only ever clear one aircraft for takeoff at a time, this is real world procedure.
I suggest looking at the ATC manual to get an overview on ATC commands and procedures. This will greatly increase your knowledge and help you when you eventually apply and become ATC. We all start somewhere, you’ll learn in no time! 🙂
@Z-Tube covered lots in his post too 🙂