Provide us FTP access to your site to find out what gives you “Notice: Trying to get property of non-object in” notice.
I suppose that this one “Notice: wc_checkout_params è deprecata dalla versione 3.3.3! Utilizzare al suo posto woocommerce_get_script_data” is because of third-party plugin for woocommerce that you use, which one I’ll be able to tell you only when I get FTP access.
Also, you need to update Visual Composer plugin but once we tried to do this we get the fatal error because of code in your child theme. Please, fix that error because the site should not crash once you disable plugin.
