I've never met a hand tool user that didn't have an opinion on this topic. I don’t mind weighing in to lend yet another opinion to this topic. I think the first two hand tools would have to be a crosscut saw and a No. 4 or No. 5 bench plane. I going to just assume that anyone woodworking already has the very basics such as a ruler, tape measure, pencil, etc. Those are just a given so I won’t mention those.
The crosscut saw is a very useful tool. Even with a shop full of power tools I still reach for my crosscut saw almost every time I enter the shop. Whether it is a cutting a few inches off the end of a dowel or cutting through 6 inches of oak, the crosscut saw requires little setup and is very quick to cut through most boards. If you're just learning woodworking and you purchase lumber that is already jointed and planed, often a little crosscutting is all that is needed to turn your projects from a stack of boards to a completed project.