The idea is just to have a bit of layers of various materials (usually carbon and nitrogen) but it's not an exact measurement and I'm sure if you don't do a full layer of the same material, your result will still be fine. But if you mean that you haven't been layering fully across the entire bed and all you would have in a certain section is the straw, then I would suggest to start planting in the areas that are ready first or you maybe plant potatoes there. Leave the other area, even another 1-2 weeks until you find the additional resources, before you plant at that particular spot.

Don't forget to add compost as one of your layers.

The newspaper works as a light block, prevents unwanted plant growth from getting the sunlight they need to grow. The straw, or other material, placed on top of the newspaper is there to hold the paper in place and hide it somewhat.
You can use just straw as mulch, but it needs to be thick enough to keep any plants that might want to grow, and you don't want to grow, from getting the sunlight they need. A "book" from the straw bale, not shaken loose, works quite well.
If you are using straw, or any other material, as a mulch do not add compost or any other nutrient source ("fertilizer") with that mulch because that can help support that unwanted plant growth which is the opposite of what you want.