First, create your desired custom sidebar. You can create a new sidebar through the following path.

Go to Dashboard > Appearance > Widgets > Add Custom Sidebar > Select a Name > Save.

Go to Dashboard > Post/Page > Page Settings > General Settings >
Sidebar ( select a type of sidebar) > Primary Sidebar > Select the Sidebar.

Under Theme Options > Portfolio > Portfolio Styling you can find and manage your portfolio archive styling and customize designs.

1. Items Styling – Customize any part of portfolio items styling
2. Read More Icon – Choose read more icon for portfolio items from icons library
3. Read More Styling – Customize read more button and icon styles

• Portfolio Template -If you want to change portfolio archive and taxonomy pages template, go to Theme Options > Portfolio > Portfolio Settings and find template option.

There are two way to access theme options and customize your website settings. In your admin bar you can find Theme Options dropdown menu and quickly access theme options panels. Or from Appearance > Customize menu you can access theme options.

Theme options controls spliced in different panels and sections and you can find any sections easily, Also some parts, in live preview frame have cog icon that will help you to access element settings quickly by only a click.

• Demo Importer – You can import full demo from library
• General – Layout, colors, styles, SEO, Loading, etc.
• Typography – Font family, size, colors, etc.
• Header – Header rows, logo, sticky, fixed side, etc.
• Footer – Widgets, copyright, footer menu, etc.
• Blog – Posts settings, styles, single settings, search, etc.
• Projects – Settings, styles, post type slugs, etc.
• WooCommerce Pro – Custom settings, StyleKits for WooCommerce sections.
• Side Identity – Site title, description and favicon.
• Menus – Add/remove menu items, location, etc.
• Widgets – Add/remove widgets from any sidebars.
• Homepage Settings – Set custom homepage and custom blog posts page
• WooCommerce – Core settings of WooCommerce plugin
• Additional CSS – You can add your custom CSS codes here
• Backup / Reset – You can download/copy theme options backup or reset theme options

If you have any available widget on your site pages, You can customize widget styling separatelly, For this purpose go to Theme Options > Widgets > Primary (According to your widget position), Then follow below shot:

• Other solution – Go to Dashboard > Appearance > Widgets you can customize any widgets styling on active sidebars.