"YOUR" and "YOU'RE"

"Your" indicates possession. "You're" is a contraction for "you are." Ex.: Is this your umbrella? You're a wonderful person.

"FARTHER" and "FURTHER"

"Farther" refers to physical distance. "Further" relates to metaphorical or non-physical distance. Ex.: The park is farther than I thought. We need to look further into this issue.