Drupal 8.x

Hi, I was following a tutorial and realized custom block after the text editor has some other options such as visibility etc... As for mine site, I only have revision at the bottom. What did I do wrong?

For my website, I have tried to add custom jquery ajax so that the content of my menu is loaded without the page being refreshed. However, instead of loading the content of my menu link, the code is reloading everything on the page like the image below

https://i.stack.imgur.com/Flc7p.png

I have used the Jquery Ajax code below to load the menu links. This code is loading all the 'hrefs' that exist on the page; I wanted to know if there is a way to avoid this situation?

I tried to upgrade from 8.7.5 to 8.7.8 by deleting core and vendor folders and reuploading the 8.7.8 version of these folders, but calling update.php fails with this message:

Hi

I tried upgrading some modules to the newest release via "Extend > Update" and selecting them. The download is successful and I get to the "/admin/update/ready" page. After a click on "Continue", I get to following URL:
https://storybat.com/core/authorize.php?batch=1&id=286&op=start 
with the error: Page Not Found - The requested page could not be found.

Hi,

I installed Display Suite and Layout Plug in mod. "Unexpected error has occurred, please check back later". I go to file manager and uninstall both mods. Site is working again but when I try to clear cache same error occurs. Using Drupal 8.5. Can anybody give me direction? Thanks.