Wherever you ask it, this is pretty much impossible to know for absolute certainty. Tool use goes back literally millions of years, and even chimps have been known to use branches as rudimentary tools. We have to rely on the conjecture that the shaped stones we find in ancient sites would have been somehow attached to a wooden handle, although bone could certainly also have been used. Regardless, we can be relatively certain that wood use goes back to some of our earliest Hominina ancestors.

It's important to keep in mind that "using wood for tools" and "cutting down trees" are two separate things. While I can't say for certain (because no one can, because these events are hundreds of thousands of years ago at least), tree-cutting most likely would've come much later. It's a very labor-intensive process without the benefit of a powered saw, and there's also quite a bit of danger inherent in the job. It makes a lot more sense for most applications to just walk around in the woods until you find a fallen piece of wood of the size and type and condition that you need for whatever it is you're doing.