A high number of free themes are embedded with malicious code and encrypted links to spammy websites or malware. Free themes are rarely updated with the frequency of WordPress updates—if they are updated at all. They also don't come with support should anything go wrong with the theme.
Use the Theme Customizer to edit your WordPress theme\n\n You can access it from Appearance > Customize or from Appearance > Themes > Customize button in the active theme's thumbnail. This loads the Customize page from which you can apply changes to your WordPress theme and see the result immediately.