You're off to a good start, here are some little tips/observations that might help you:

1/ Your header file should contain the structure definition as well as the function prototypes for functions related to that structure. So basically you should move the function prototypes into your header. Remove the last line of the header, you do not need/want it there.

2/ You will need some variable that keeps track of how many people are currently in the address book. You need this so that you know where in the array to add a person.

3/ In you addPerson(), you do not need to loop, and you should not redeclare the array. Instead you should copy the contents of the given person to the index of the array that you are currently on (as mentioned in #2).

4/ getPerson() should not loop either. You should have a variable somewhere that keeps track of what index you have looked at last so that the next time you call this function, you can get the next person after that (and increase the index).