Following are some major differences between GA4 and GA4:
If you are unable to find your Tracking ID (i.e. "UA-123456-7" ID), it's probably because you are in a Google Analytics 4 property instead of a Universal Analytics property. You might have set up a Google Analytics 4 property (now the default) for your website instead of a Universal Analytics property. So, in this case, you need to find the measurement ID.
There are a couple of ways of setting up a new Google Analytics property for your site. First, you need to set up the analytics account. If you already have the analytics account, you can proceed with the next steps. Here’s how you can get started with setting up a property alongside your existing Universal Analytics:
Now, your GA4 property will be created.