While I'm running Zorin OS 16, it automatically restarts itself
Hi and welcome to the forum.
Did you download the .iso from the zorin website and verified it ?
Two main causes for this in my experience are graphics card issues and over heating , but it is possible something went wrong during the installation. Could you please tell us about your computer.
@SVSM_1745 Can you also tell us which edition of ZorinOS you have e.g. Core, Lite etc.
Also please edit your forum profile to indicate that there, to avoid us having to keep asking you that question in future.