Like other Smash Bros. games, you'll be able to unlock different things like Music, Mii Outfits - and of course - Fighters. This page will guide you on
Super Smash Bros. Ultimate: How to Unlock Every Character (Fastest Method) - IGN
Spirits - Super Smash Bros. Ultimate Guide - IGN
Spirits - Super Smash Bros. Ultimate Guide - IGN
World of Light Character Unlocks And Map - Super Smash Bros. Ultimate Guide - IGN
How to Unlock Piranha Plant - Super Smash Bros. Ultimate Guide - IGN
Mysterious Dimension - Super Smash Bros. Ultimate Guide - IGN
Super Smash Bros Ultimate characters: every playable Fighter
Super Smash Bros. Ultimate Guide - IGN
Spirit Board - Super Smash Bros. Ultimate Guide - IGN
Kirby - Super Smash Bros. Melee Guide - IGN