Need help to make messy hair...?

I'm a 19 years old guy

My hair is straight and is 2in long on the top.

I want to have a messy yet controlled hairstyle (fits me the most).

What would I have to ask the barber to do to have a controlled "messy" haircut (I also use this mousse thing by Dove, is that a good idea?) that I can grow a bit longer in the future?

Need help to make messy hair...?

Just talk to the barber about what you want, they would be the most qualified person to help you make a decision. Good luck!