Macro Photography is a close up look at small subjects also it creates a small depth-of-field, which means that the backgrounds will get blurry sometimes. Macro is good thing because it focuses on the most important part of the subject.
Leading lines are lead us strait to the point. Leading lines take us visually through the picture without any detours. Leading lines lead the viewer's gaze into and around the image.
The Rule of Thirds is a compositional trick to help position a subject outside of the center of your photograph. On your camera you have a display grid and it shows how to divide your picture plane into thirds both horizontally and vertically.