The first tab under Grow > Settings is the General settings tab. There are several sections here and you'll find some information about each one below.
You'll want to enable this if you are wanting to use bit.ly to shorten your share links. It's not something that is required at all!
Social Shares Recovery
You'd use this section if you have moved from HTTP to HTTPS or have a change in permalink structure across the site or a previous domain.
If you need help in determining what your previous permalink format was, here is a great resource! If you have a custom permalink format, this resource will help you determine the field names. If you have questions, email firstname.lastname@example.org and our team will be happy to assist!
Google Analytics UTM Tracking
This setting will allow you to see in your Google Analytics more information about where your traffic is coming from, in terms of any marketing campaigns.
It will show you the traffic that came in to your site originating from those sources, i.e. the people who clicked on the URLs that users shared via Grow Social Pro.
You'll want to enter your license key here.