You need to have a specific follower to activate the shrines, Mystic Melody. All followers have a special horn noise activated using the look back button depending on your control scheme. USUALLY the most consistent way I've found to activate the horn is backing up & then trying to use the horn. Takes a bit but it's so far the only way I've found using the horn. Now as to getting this specific follower, they're obviously locked behind a challenge that you can only complete after playing the egg cup; the 14th & final cup of the main set. You'll have to find a secret in Lost colony to unlock the follower. To help keep your search a minimum, you don't have to go THAT far into the track to find it as it's pretty early on. After the first trick jump in the crates spiral room, you're able to get onto the ceiling if you double back before exiting the room. A glowing aura circle will be on the ceiling above the shortcut ramp in that room.. There's ALSO a shrine in the stage required to unlock the follower too, but I'll let ya find that out on your own. Just remember to look behind you often.