You can change the default SSH port 22 of your server in order to make people difficult to access your server. Port 22 is a standard OPENSSH port on Linuxservers. However, if you wish then you can change this number to some non-standard port by following below steps:
1. Open /etc/ssh/sshd_config file
2. Look for line Port 22 and change the new port number.
3. Restart sshd server.
Hope this will be helpful.