A similar project in scope, for some inspiration, is renovation of Maple Leaf Gardens in downtown Toronto a decade ago.:
https://www.google.com/maps/@43.6618...7i16384!8i8192
See some detailed images here:
https://www.blogto.com/city/2010/10/...dens_makeover/
In summary:
Basement: Parking
Main floor: converted to a Loblaws (Superstore)
Second/Third floor: Liquor Store, Joe Fresh clothing. Ryerson University space, Gym.
Third/Fourth+: Smaller hockey arena, reusing the nosebleed sections of the original arena.