The Events & Tasks tab lists your band's events. Opening one shows its details and, if it's expecting an RSVP, two big buttons: going or can't make it.
If you have attendance-management rights for your band, an event's detail screen also shows the full list of who's going, declined, or hasn't answered yet — tap one of the three counts at the top to filter the list by that status.
Each person's row shows their current status as a plain, non-tappable pill — tapping it does nothing, on purpose, so a stray tap can never reassign someone's attendance by accident. To actually change it, use the small pencil icon next to their name: it opens the three choices (going / declined / no answer) so you pick deliberately. The counts at the top update immediately once you do.