As you might already know, a large number of websites in China are blocked by the “Great Firewall”. Among the websites there are Google, Facebook, Youtube, and many more. The only way to have free access to everything while browsing the web in China, is through a VPN (Virtual Private Network), which masks your I.P. address so that your laptop appears to be connected from the U.S. or Japan, even if you are in China.
There are many options when choosing a VPN, both free and fee-paying. If you have Macbook/iPhone you can download the VPN also once you are arrived in China, if not, be sure to download it before leaving from Italy, since it is impossible to access google play store (for Android users) without VPN!
For fee-paying VPN, at the moment Express VPN is one of the best (https://www.expressvpn.com/). When buying it, I suggest to buy no more than 6 months, since your VPN could stop working, or a better one could come out! Regarding the free versions, ArchieVPN is good for Android (you can find it on Google Play store), while Betternet works very well on iOS.