Can you post on pages?

Hi, I am a new user of WordPress and recently have set up a website using the Manifest theme at wavecomposition.com. My question is whether I can post directly onto the pages (Essays, Interviews, &c., About) that I have set up, and if so how? Currently I can only post onto the home page. If not, is there a way of retaining the current display (with the page names linked across the top of the website) and then automatically sorting any posts I make so that they go onto the appropriate page?