I am unable to find system properties like in screenshot. From where I can see that option?
It looks like the screen shot you have pasted is from previous version of ServiceNow. See the latest way of system properties. Click on the type of properties you want to edit or see like CSS/System/email etc.
If you want to see all properties at one place,
1. Write sys_properties.list on left navigation and press enter. You will see list of all system properties.
OR
2. Go to Tables --> System Property --> View all properties data
