For a single ASA and if you don't require historical or detailed reports, ASDM can suffice. For any other use case, we recommend FMC.
How to install FMC IS thoroughly covered in the Installation Guide and this document:
http://www.cisco.com/c/en/us/support/docs/security/firesight-management-center-virtual-appliance/118645-configure-firesight-00.html
For policy setup I recommend a new learner review the Lab Minutes guides that cover this in depth with step by step videos It's free to stream here:
http://www.labminutes.com/video/sec/ASA%20FirePower
Also see the free presentations at Cisco Live 365