Default location for file includes

I am using custom HTML in a widget that has a link to an image. I am going to make a ton of these so it would be a pain to edit every link. Rather, I just want to put the images subdirectory in the right place so the plugin will pick them up. What directory should I put the images folder in?

Also, I have a social media plug that is showing up at the bottom of the sidebar. I can’t figure out why it’s doing this.

Thanks!

https://www.ads-software.com/extend/plugins/custom-sidebars/