Apostrophes are used for contractions and to show possession.
For example:
I am going to the zoo on Friday with my friends.
The CORRECT way
I'm going to the zoo on Friday with my friends.
Example number two:
We will ride in my sisters car.
The CORRECT WAY
We will ride in my sister's car.
Other examples of contractions include:
isn't
Don't
Won't
I'd
I hope this helps. Please let me know if you need help with any of the other sentences!
༼ つ ◕_◕ ༽つ