I don't really get it 😢

Slurp! The key is to train the Champion's stats like running and swimming, and equip gear suited for the terrain. As they say, 'A journey of a thousand miles begins with a single step,' so let's reinforce our gear by opening chests daily and steadily build up our victories. Hmph!

For number 1, you can increase your stats by opening the training bag while progressing through the game. For number 2, just steadily collect gadgets. For number 3, do the events whenever you have free time. You don't need to worry about number 1 because your stats will increase sufficiently with grinding, but number 2 isn't easy as it also depends on luck in acquiring gadgets... Good luck!