They are not hard to hook up at all, I did mine. You do need to make sure the line is deeper than the frost line, a local plumbing company would know what that is in your area. If you run your line under an area that is plowed in the winter, it needs to be deeper.
I had a neighbor with a backhoe dig mine. Then the bottom is covered with a 3-4" layer of sand, then your line, followed by more sand, then a layer of foam insulation board, then backfilled. The sand reduces the risk that rocks will damage the line, and the insulation protects from freezing.
At the point of connection to the hydrant, dig a deeper area and fill with sand if the soil that deep is not well-draining. The hydrant empties some water out the bottom each time it is turned off. Then back fill with sand, just in case you have to dig it out again in the future, much easier than digging up dirt.
Follow the attachment instructions closely. If the hydrant is twisted after being hooked up and buried, the fitting will come apart and you will have to dig it up. I put in a wooden post next to the hydrant to protect it from damage.
I put a few bags of pea stone down at the top of the fill, to allow better drainage.
Use black pex water line, size depending on your source. Mine is 1" and it comes out like a fire hose, It is attached (by a plumber) at the house to the water line that comes into the house from the well (before the pressure tank) and has great force. Make sure they install a shut-off valve as well.
I layed a power line down in the same trench, on top of the sand, below the insulation board.
While you could certainly dig the ditch and place the line, then leave it for later, it would be easier to do pipe and hydrant all at once, so you don't have to re-dig the end where the hydrant goes. You could do the hookup at the house end later.