New player...feel like I have an impossible task..what am I missing?

I just started playing 2 days ago. I have a task where I have to rebuild 2 barracks. I'm at 1/2. Found out that I have to demolish another building to build a 2nd barracks. But everything I'm trying to demolish it says my capitol has to be at level 15. Right now my capitol is level 6 and I'm nowhere near having the requirements to level up. And I have to do this 8 more times. Is there another way to achieve the 2 barracks task?