Just because you don't know enough code to create your own WordPress theme doesn't mean you can't easily make changes to an existing theme to fit your needs. One of the ways WordPress allows theme authors to include simple customization options is with widgets.
With widgets, customizing certain parts of your site is as easy as dragging and dropping. If your theme supports widgets you'll see a link to "Widgets" under the "Appearance" section of the dashboard. There you'll see which sections the theme developer has enabled widgets for. WordPress includes some built-in widgets and the WordPress extension directory has thousands of plugins offering all kinds of widgets.
Widgets are just one of the many ways WordPress makes managing a website easy for non-developers.