I would lean towards a parenting class than a child psychologist unless there are other warning signs that something is 'off' with your child.
Not because it would be harmful at all, but because you should realize that most 2 yos are aggressive. That is what they do. They are learning how and when they need to control their impulses and communicate in socially acceptable ways. As a parent it is helpful to find some tools to help you manage their behavior better, and it will put things in perspective.