I have a Minecraft Server and I would like to add buildings to it. Is it possible to do so without making them myself? I would like to have a beautiful house or a big church.
It's your server. It's technically stealing to download maps and use them on your server.
If you need people, try one of the chat rooms here or on Minecraft Forums to hire staff and builders. Or ask your friends with Minecraft.
You can also download plugins like worldedit.
download mcedit from http://www.mcedit.net/
open your server folder and there should be a folder named 'World' right click that and click copy.
download a map online, i suggest getting from planet minecraft or minecraft forums.
click start, and in the search bar, type '%appdata%, and go to worlds. here, click 'paste' also put in the world you downloaded that you will get the buildings from.
open mcedit that you downloaded earlier, and open the world you downloaded, then select the building with the selector tool on the toolbar, and select copy. you should see something in the top right corner that says 'save' click that and save it where you can easily reach it later.
exit that world, and open the one from your server. click the paste button and position it where you want.
click save and close, then put the world folder back, and you should be done!
You can build them easily by using world edit. You should download spigot and install worldedit's jar file, you may also want to install worldguard.