Medals are the 6 dotted rings on your profile selection screen in Super Mario Bros. Wonder. After returning to the title screen, hit the buttons shown to start
World 6 - Item Park Search Party All Wonder Token Locations - Super Mario Bros. Wonder Guide - IGN
All Secret Exits and Hidden Wonder Seeds - Super Mario Bros. Wonder Guide - IGN
How to Get Every Medal and 100% Clear the Game
List of Badges - Super Mario Bros. Wonder Guide - IGN
Walkthrough - Super Mario Bros. Wonder Guide - IGN
List of Badges - Super Mario Bros. Wonder Guide - IGN
Super Mario Bros. Wonder: How to Get All Medals (& 100% Completion Rewards)
Finally 100 percented the game. : r/SuperMarioWonder
World 2 - Puzzling Park Search Party All Wonder Token Locations - Super Mario Bros. Wonder Guide - IGN
List of Badges - Super Mario Bros. Wonder Guide - IGN, badges