Hey Leslye,
glad to hear the URL issues have been resolved!
In order to assign a specific custom sidebar to the blog posts page, you’ll need to visit the “Default sidebars” tab of the “Appearance -> Custom Sidebars” admin section, click on the “Main blog page” under the “Default sidebars for archives” section, and choose the required sidebar from the drop-down; I’ve done this for you, please check that the widgets displayed on the blog posts page are proper ones at the moment.
Sincerely,
Andrii / Satori Studio