Yes, I'm horrible when it comes to using those words.
Like when to use they're and when there and when their and when you're and when your..
you're is only when it's short for "you are", otherwise it's your.
they're is short for "they are" (as in, "they spent so long looking for Prime deals that they're going to be tired tomorrow". "there" is referring to a place (as in "here and there"), and "their" means "belonging to them" (as in, "they ate their snacks on the bus").