Show three Photos und er the Header Photo

Hello! I am very new tow Word Press, and pls forgive my poor English..... I think it is very pretty with the three Photos in a row under the Header Photo. But how do you place them there? In our Website you can only see new "Beiträge" under the Header. And how do I get a "Home" Button into the Main Menue? https://www.funnydoves.de