An email address and a password. About twenty seconds.
2. Click the link in your inbox
The only hoop, and what stops one person taking every good tag.
3. Type your gamertag
One name across the whole site, not one per game. Yours while you sign in every 30 days.
Optional: 8 games can prove the account is really theirs and earn the lime check. Read from the platform after you sign in: CS2, Chess.com, Deadlock, Dota 2, League of Legends, StarCraft II, Teamfight Tactics, World of Warcraft. You do not need any of it to hold your gamertag.