Do one thing at a time. Focus on Daily Notes. Make sure the plugin is Enabled. Even though it says “Inbox”, change it to a different folder, and then change it back to Inbox, make sure its the full path. Don’t just type “Inbox”. Erase that and click the field to see all the folders and pick the correct one.
You mentioned that you couldn’t find the plugins under Core, they are Third Party plugins, and are under the Community Plugins.
Worst case, uninstall the plugins, close Obsidian, reopen Obsidian, reinstall the plugins, Enable the plugins, Change the Settings to the desired folder.