How long does indexing take?

Why am I not indexing on search for simple, dimensions based keywords?

I sell a 20″ x 20″ plastic sheet, which is available from other sellers in other sizes like 12″ x 18″, 6″ x 6″ etc, but only I sell 20″ x 20″. But even if I search “PRODUCT NAME 20″ x 20” I don’t show up in the first 100 search pages, all the results are filled with inaccurate sizes and items (to the point it suggesting downright random items).

I have a new account, and am FBM, do I simply need to age my account and recieve positive customer feedback on my store, while being unsearchable? (I am searchable by brand-name, and ASIN only, any general search without that specific data will not index me as a result yet).

Is there a blackout period when you are a new merchant? Or upload a new product?