Missing Amazon package

So I ordered something from Amazon back in late November. Along with 3 other items, and they were done on two seperate transactions. The package I'm concerned with says it was supposed to ship by Dec 15. So it's been a month. No package. Went to dragonfly website and copiy and pasted the tracking number, and it says it doesn't match any of their current deliveries.

I rarely order anything online so I don't really have any experience dealing with what happens when you don't get your package.

Any advice on my next step?