Some general notes on common grammatical confusions:

its is a possessive pronoun like mine, hers, his & ours. Just like mine, hers, his & yours, it never has an apostrophe.
it's is a contraction, a shortened form of "it is".

If in doubt, substitute "it is" for its/it's and see if it still makes sense. If it does, use it's.

your is a possessive pronoun like my, her, his or our. Just like my, her, his or our it never has an apostrophe.
you're is a contraction, a shortened form of "you are".

If in doubt, substitute "you are" for your/you're and see if it still makes sense. It does, use you're.

yore is times past, it has nothing to do with you, unless you're feeling very old.

their is a possessive pronoun like my, her, his or our. Just like my, her, his or our it never has an apostrophe.
they're is a contraction, a shortened form of "they are".

If in doubt, substitute "they are" for they/they're and see if it still makes sense. If it does, use they're.

there refers to the place, rather than this place which is here.

It has nothing to do with they, unless they are over there. If you have trouble remembering, note that 'there' contains 'here'. Here & there - places, not people.