To update theme first you have to download the latest version from ThemeForest. After downloading the theme goto Appearance->Themes. Then activate any other theme than Listbook theme. After activating another theme you have to delete the Listbook theme. To delete the Listbook click in the listbook theme grid and it will open popup. In the right bottom corner of the popup, you will get a button to delete the theme. Delete the theme and then install active the new theme in the usual way.
In the theme package you should get a file named listbook-child.zip. Upload this zip as theme and activate it. Make sure you have already Listbook installed. Both child and main theme must have to be installed but child theme have to be activated.
To optimize your site you can use below two free plugin. You can also configure CDN and for object caching you can also use redis if your server support it.
You can use any other caching plugin.
Check the Gutenberg Blocks->Section & Homepages section in documentation.
To create category and feature relation for listing submission page flexibility. First you have to goto Listings->Category menu and then click on edit in any category
From there you will get a field called Related Features. It is a multiple selection selectbox. Select the related features for the specific category
After deactivating and reactivating the theme my site is broken nothing is showing properly. How to fix?
make sure Listbook Helper and Listbook Algolia plugin is active. If not please activate these plugins. These to plugin got deactivated when listbook theme is not active.
Make sure you have configured your algolia settings and sync all data. Check Plugin->Listbook Algolia chapter in documentation.
Make sure you have configured google map api keys and in your google map account billing is enabled. Check Plugins->Google Map chapter in documentation.
Make sure you have selected the explore page in the Listbook Settings. Check below image