It is normal to feel dislike or resentment of a stepparent, especially when you are first adjusting to things.
Chances are, you have a few things in common. Try focusing on the things you like about your stepparent. It can help to talk about it with an adult friend who has an objective perspective.
If you talk to your parent, don't say that your stepparent is all bad. Instead, tell your parent specific things you don't like about your stepparent.