Hello,
1) This area is Prefooter widget area and static block there. That’s why if you want to change content go to Static Blocks > edit Prefooter static block and last column content http://prntscr.com/cqvs02
https://www.8theme.com/demo/docs/xstore/#theme_settings_44_static_blocks
2) Go to Appearance > Widgets > remove 8theme – Static Block widget from After the products widget area http://prntscr.com/cqvszr
3) Go to Pages > edit My Account page > scroll down to the 8theme Layout options and just disable sidebar on that page. All the pages by default displays Main widget area. If you don’t need sidebar you can disable it in page settings. If you want to change sidebar content add necessary widgets into Main widget area, it will replace default search widget.
Regards