Do あなた think/believe that there is good and bad in everybody? That everybody has a good side and a bad side?

(Edit- my original answer didn't make much sense, so I tried to clear it up some.)
Meh. I don't really think people have good sides または bad sides, because very few things come anywhere close to being objectively good または bad. Most things that we think of as being "good" または "bad" are things we've subjectively 与えられた those labels based on our own moral principles and upbringings.
I don't think there's many people that do things just for the sake of being good または bad. Most people just act on their own morals, and what one person may see as a positive thing to do may be a negative thing for someone else.
Just in general I think human behavior isn't something that can be easily summed up as being "good" または "bad". It's not that simple.
I don't think that the whole "everyone has a good side and a bad side" thing is wrong によって any means, but I think it's もっと見る complex than that. To just leave it at that without diving at least a little bit もっと見る into human nature is an extreme oversimplification in my opinion.

''Good'' and ''Bad'' are pretty generalized terms. However, yes, there can be two different sides inside of us. Light and Dark, Positive and Negative, Yin and Yang, Black and White which are making the Grey that comprise us whole. Each person can have different aspects of their personality which they bring outside, most times also depending on the situation !!!!

i think its upto you
あなた can feel " Bad" doing certain things but others may think its " Good"

Yes.