Normally when you see a lot of messed up lettering like this on the store page it is because your have some other content on the same page as the store shortcode. You cannot have any other content on the store page.
To answer your question about restoring your products: When you deactivate the store there is a warning message that by deactivating the plugin you will lose all your information. When you deactivate the plugin it removes all the database tables that it created and the additional folders (such as the product images folder). When you reactivate the plugin it will recreate all these tables and fill them with the default products again.
The only way you can get your products back was if you have done a database backup from before you deactivated the store. This can be done from the Admin > Tools > Database Backup, although I would advise doing it directly from within your hosting control panel or SQL.
I urge everyone reading this to routinely back up their store and even their entire website, especially if you have put a lot of time and effort into it.