Make sure there's absolutely no wind. Those one-handed clamps and temporary lumber for bracing really come in really handy. You'll probably also want to get the foundation totally complete first, so you can then get the structure all assembled in one day. A lot of metal structures are essentially membrane structures, which aren't strong until they are complete, so you don't want to leave it overnight partially complete.
Looking at the picture on the box, you're really going to want some help, or a tractor with a loader, or something. It's possible if you are supposed to assemble trusses and then lift them into place that will be really difficult by yourself.