Collective nouns often describe groups of animals (e.g., a flock of birds, a herd of elephants) or specific objects (e.g., a fleet of ships, a bouquet of flowers).
If you're looking for a word to describe a group of similar things, you could use a more general term like:
* Collection: A gathering of similar items
* Set: A group of items that belong together
* Ensemble: A group of items that work together as a whole
* Assortment: A variety of items
* Array: A large group of items arranged in a specific way
Let me know if you have another word in mind, and I can help you find the right collective noun!