As a possessive pronoun, your shows ownership; something is belonging to the person/people you are addressing. This means it will often feature in a sentence with an object.
E.g. ‘Is that your hat?’
It is also a complete word – meaning it isn’t a contraction – and doesn’t take the place of multiple words in the same way you’re does.
You’re is a contraction. The words ‘you are’ are contracted for ease but the meaning does not change. The easiest way to use you’re is to think of the full form, and apply that to your sentence.
E.g. 'You’re amazing!' is the correct usage and we know this because 'you are amazing!' would make perfect sense.
Unlike your, you’re is direct and will often be followed by a phrase or adjective.