Your: refers to something you own
Is that your bike?
You’re: an abbreviation of ‘you are’.
You’re going to work tomorrow.
Yore: referring to the past, although it isn’t often used now
In days of yore, a Lady’s ankle was never seen.
Although these three words sound exactly the same, they obviously can’t be used as substitutes for each other. No catchy memory tricks for this one – you simply need to remember that the apostrophe replaces the a in you are to create you’re.