You definitively have to go and see the Cliff Divers, this is a must in Acapulco.
The San Diego Fort is beautiful and is in front of the Ship´s Terminal, and if you like history you will be able to learn a lot of this port history.
The Chappel of Peace has amazings views of the bay.
The Flamingos Hotel is the best place to watch the sunset.
But if your looking for different activities, you must check the tours for shotover, bravo rafting, swim with dolphins, some tours includes the fort, chappel of peace and beach.
There's a lot of stuff to do while you are here! :d
Greetings from sunny Acapulco!