how to increase width of sidebar

You’ll need to create a child theme and add some custom CSS for that. I have instructions for creating a child theme here: https://www.competethemes.com/documentation/ignite-knowledgebase

i add child theme but now i need code to increase sidebar and body width using custom css…

I’m sorry but I can’t write custom code for you. To get you started, the sidebar has a class .sidebar-primary-container with the width set on it and the body content has a class .main used to set the width.

Because the site is responsive, the sidebar sites below the main content until 900px so make sure not to adjust the width until the screen is 900px wide using a media query.