You're- Contraction of you are.
Your- Used as a modifier before a noun
- A person's; one's
Their- Used as a modifier before a noun
They're- Contraction of they are.
There- At or in that place
- To, into, or toward that place
- At that stage, moment, or point
- In that matter
To- In a direction toward so as to reach
- Towards
Too- In addition; also
- More than enough; excessively
- To a regrettable degree
- Very; extremely; immensely
Two- The cardinal number equal to the sum of 1 + 1.
- The second in a set or sequence.
"It's" is only used when combining "it" and "is".
Don't forget "than/then" and "common" is NOT the same as "c'mon"/"come on". "Lose" and "loose" are not the same. "Of" is not the same as "have" (ex. "I should OF done that" is so incorrect that you should HAVE been smacked for writing something so moronic).
Now use them correctly, idiots.