Hi Rama,
1. For AAM To Target Segment Sharing, nothing as such needs to be done at AAM level or Target level. You just need to get your Organization provisioned for Shared Audiences/ Profiles and Audiences/ People Core Services. For provisioning your account for Shared Audiences, please fill below form:
https://adobe.allegiancetech.com/cgi-bin/qwebcorporate.dll?idx=X8SVES&preview=1&design=1
Once People Core Services gets provisioned that means Segments Sharing functionality is actually configured at your Audience Manager end in the form of Data Sources and Destinations and as well as in Target setup. So, you need not to do anything at your end. Once configured you are all set to share Audience Manager Segments to Target with the help of Marketing Cloud Audiences.
2. You actually need to go though People Core Services provisioning for this. Without Core Services, you will not be able to share AAM Segments with Target.
Hope this explanation helps. :)
Thanks,
Ankit Bhatt