Yes, I do with my parents but my sibling. - Yes, I do have a good relationship with my parents but not with my sibling.
My mother and dad always cheer me up to become one who I hope to be. - My parents would always support me to become the person who I wanted to be.
On the other hand, my elder brother harasses me all the time teasing with strange things. - On the other note, my brother would harass me all the time and teases me with strange things.
Whenever I say stop, he doesn't care about it.
I think he doesn't have an idea that we can be in a good relationship. - I think he doesn't know that what he is doing is tarnishing our relationship.