LaTeX will automatically handle the numbering of sections and chapters for you. You can suppress adding sections to the table of contents, as well as section numbers, by using the starred version of the command.
This is also useful if you are writing an article with no table of contents, and do not want numbers to appear for each section.
The list of figures and the list of tables command places a list of all figures and tables in your document. The list is inserted at the location of the command. If the caption command appears in the figure environment, that figure is added to the list of figures. If the caption command appears in the table environment, the table is added to the table list. The text of the caption is what's displayed in figure or table list.
To generate the initial list of figures, tables, and table of contents, and need to run the LaTeX command twice.
% latex latex-file % latex latex-file