In my life I have judged many books by their covers.
I have felt very uncomfortable around many people.
And I have refused to associate with people based on something I know, or think I know, about them.
I did not hate these people. I simply did not want to deal with them. I did not want to know them, or be their friend.
Anything beyond that could be called hating, or a sense of insecurity or jealousy within myself.
So basically, if they don't like you for whatever reason, and leave it at that...I doubt they hate you.
If they go out of their way to make sure you know it, that is a different story.
I would forget about it, and realize that there will be people who don't like you because of the way you look, the color of your skin, your sexual orientation, where you are from, what you drive, how you act...etc...etc.
But if they start making threats, or try to upset you, that is when you need to worry.