Sticky sidebar

Hello, Team Customify

I want sticky sidebar for my website. How I can do that, this feature will help the user experience better and can navigate easily whatever they want.
Please assist me with a better response to this.
And the other thing I want for my website is the featured recent posts or widgets. Where there will be featured images and text this will give a classy look. Please work for this and assist me how can I use this feature

Thank you!

The page I need help with: [log in to see the link]