You're is a contraction of You are. You're not going to brush your teeth with that thing? (Note: your teeth, the ones belonging to you. You're not going to, you are not going to do that!)
Yore refers to the past. It is an archaic word. Very few people use it anymore. Borne on the night wind, voices of yore, come from the far-off shore.
Their, there, and they're.
They have taken their car (the one belonging to them) and driven over there (that place), where they're (they are) going to listen to ear-shattering pop music.
Brilliant writers like Margaret Wander Bonanno are allowed to play with words like that when talking to/of the s. oteri. No one else. Well, maybe elementary school students, but they don't know any better.