There are several “default” widgets in a normal WordPress installation, which might be active on your site depending on your theme and how you’ve customized the site. Normally you would go to Appearance->Widgets to customize any widgets and sidebars for your WordPress site. Was there a particular widget on your site you wanted to customize?
i want to remove some of default widget item.but i wonder what file to edit or i would better to create a new widget?
Circling back around – to create a new widget, check out the documentation here:
https://codex.wordpress.org/Widgets_API
thanks.
it was a very good reference.