I realize you are new, but seriously, use the search button. There have probably been several hundred threads created exactly like this. I am not trying to be mean, I am just trying to save you from the Angry Blue Monkey and his ban hammer. To start out, you should probably build Garland's Marine armor, because it is very simple to construct. And, you can find pepakura files on the Costuming Wiki, at the 405th Pepakura hub, or at the numerous file bases of the skilled modelers here in the 405th Division.