Question: "Why does Earth’s surface change? How does Earth’s surface change?"
Answer: "Earth is a system of frequent interaction between the surface conditions, interior, and external events. Many of Mother Nature's lets say 'Natural Disasters' is one of the many things that help to mold and shape our planet. Take, for example, volcanos into consideration: when the eruption begins within a volcano, it pushes up new material from underground, helping to create new land forms (this was how many of Hawaiian's islands were created.)
Shifting of tectonic plates within the Earth's crust and upper mantle is another reason. The plates are constantly interacting, and lets say, 'grinding' together, as well as some colliding and breaking apart. Any of these reactions to the shifting of the tectonic plates can build any of our landforms and landscapes (including mountain ranges, oceans, valleys, etc.)
Also, another case of nature, erosion of the surface from water, wind, sand, chemicals, and living land creatures can develop and mold the surface of Earth as well. Countless numbers of forces are frequently breaking down and departing the surface, moving and spreading the materials of the surface to other sides of the Earth, later on perhaps building new formations."
^I understand this is a lot to read and probably more than you were hoping for, but I hope this can at least point you into the right direction. Happy Early Valentines Day!