Sticks:
* Bundle of sticks
* Pile of sticks
* Heap of sticks
* Clump of sticks
* Stack of sticks
Flags:
* Banner of flags
* Display of flags
* Field of flags (especially if they are planted)
* Array of flags
* Collection of flags
* Stand of flags (referring to a group of flags raised on poles)
You can also use more general terms like group or set for both sticks and flags.
The best choice depends on the context and the specific situation you're describing.