Many people mix up ‘you’re’ and ‘your’.

Apostrophes show that letters have been left out, and words have been joined together. So ‘you’re’ is short for ‘You are’.

You’re late.
You’re coming with me.
You’re not wearing that!

Your is a possessive pronoun:

Is this your book?
Put away your cellphone.
Enjoy your holiday

So when in doubt, if you can rewrite the sentence with ‘you are’ and it makes sense, then use ‘you’re. If it makes no sense – Is this you are book – then it must be ‘your’!