The World Handicap System (WHS) instituted changes to the handicap system beginning January 1, 2020. These websites offer information about the WHS system: www.usga.org/whs OR www.lpgaamateurs.com
If you have never posted a score, want to establish a handicap, and need step-by-step instructions: Starting a Handicap
To answer in-depth questions about handicapping (what it is, why to have one, how to post, net double bogey, see below: