The Admin page in Google Analytics gives you access to the Analytics administrative features. At the bottom left of the page, hover over the gear icon and click Admin to open the page.
The Admin page for a Google Analytics 4 property has different options than the Admin page for a Universal Analytics property.
For example, in the Google Analytics 4 Admin page, there is a Data collection and modification section, which doesn't appear in the Universal Analytics Admin page.
And in the Universal Analytics Admin page, you have a column for Views, which are not a feature of Google Analytics 4.
Admin page for a Google Analytics 4 property
Admin page for a Universal Analytics property
Use these tools to create new properties, change user permissions, add integrations, set up filters, import data, and more.