Do black holes have a direct effect on earth? If so, how?

The Schwarzschild radius, beyond which light cannot escape, is the limit of a black hole's gravitational pull, and beyond that point, a black hole's mass is no different from that of any other object.

The massive black hole at the center of our galaxy has millions of solar masses, but it is tens of thousands of light years away, so it has even less impact on Earth. Similarly, a typical black hole formed from the collapse of a massive star might have a mass equal to several times our Sun or maybe several tens of solar masses, but it is many light years away -- too far away to exert much gravity on Earth.

There are no black holes near enough to Earth to have any discernible gravitational pull or other effects, and their gravitational influence rapidly decreases with distance, so black holes have no direct effect on Earth.