The amount of crema is directly related to the time elapsed since roasting - the beans gradually degas - this process starts immediately after roasting. They will have very little gas after about three weeks..
Do yourself a favour Terry - ditch the pre-ground coffee. Get the beans from a source that prints the roasting date on the bag and grind the beans immediately before extraction.
You will be amazed how much better fresh coffee, freshly ground tastes
I would recommend; https://shop.squaremilecoffee.com/