Have a look at that word 'Confirmación' again. In Spanish 'Con' means 'With' and 'Firma' means 'Signature' and this is the root of the English word 'Confirm'. When you say "I confirm I will do it" you are partly speaking the latin and meaning "I, with signature, will do it"
Now you'll start to notice more and more English words that have their roots in Spanish:
One other thing to notice here is when you put 'q' and 'u' together the 'q' takes a 'k' sound. Watch out for this in the future and you'll spot the pattern making it easier to pronounce new words correctly.