I need someone to explain how to balance chemical equations PLEASEEE?

For chemistry, what you are looking for is to have the same number of elements on each side of the equation. For you example, the left side has 1 Zn, 2 H, 1 S and 4 O. On the right side we have 1 Zn, 1 S, 4 O and 2 H. Everything matches up. The equation is already balanced