At $20, this concolor fir is overpriced. Try offering less after Christmas. Maybe you'll get a deal (you, of course, are the judge).
Concolors remain flexible for quite a long time, so those straight stems could be bent into some interesting curves, you just need some copper wire that is about 1/3rd the thickness. This is something you could do, in your garage, as soon as you have the wire.
The needle size of firs cannot be reduced much in size per my experience, so a good bonsai would likely need to be fairly large. The game is the same as with pines; you need to let a sacrifice run to thicken what will be your trunk, then remove the sacrifice when the lower trunk section is as thick as you want + rinse&repeat. Of course, you don't have to do that. Meanwhile, you could also remove those weeds and pull off enough of the soil to see the base of this tree - does it have any nebari and, if so, at what point of view does it seem most interesting? You wiring/styling of the tree ought to agree with this or you need to find the most pleasing compromise.
Come next spring, as the buds swell, you could repot it. You should be able to remove all of the nursery soil and transfer it to a bonsai substrate. You'll then need to secure it into the same plastic pot, another plastic pot, a pond basket, a colander, a grow bag, or a bonsai pot (your choice). Then watch it grow. As the new growth 'hardens' and you see buds at the tips, you should look for buds beginning to form at the bases of some needles. You can cut fir back to a bud, but any stem that doesn't have a bud at its end will become a dead stem, once the needles drop, which they will do after a couple of years or so.
My point is that there is a lot you could learn from this tree.