Look anons, I'm going to level with you. Grixis is very VERY difficult to build if you don't know what you're doing. In general Grixis is strong because it combines blue's fuckery, with a splash of black sadism and red's reckless abandon. It is literally the colour combo for edgelords with too much money. The manabase is tough to get, mana fixing is hard to find, and while you have oodles of card draw, you really need to understand what your wincons are, and how to enable them.
All that aside, if you want your Precon to be used well, there are a couple of options for a new player. First, lets look at commanders:
>Nin
Pretty straightforward. Ramp hard, ramp harder, hit something with Nin's ability, and draw a bunch of cards. You can ping something like Stuffy Doll to cause all sorts of bedlam, and it's honestly pretty fun.
>Azami Wizard Stuff
This deck is also pretty simple, and generally hated. You grab every monoblue Wizard, throw them into a deck, tap them to draw cards. In theory you play things that fuck over people's hands, and use Azami to make the lock asymmetrical, or your ramp, shit out a billion mana, draw a bunch of cards, then combo off in some elaborate way.
>Marchesa
This one is fun, but the manabase is expensive. The idea is to use things that send creatures to your yard, recur them with your commander, and abuse the shit out of some +1/+1 shenanigans. The idea is to take a bunch of strong creatures with good ETBs, and kill them over and over again.
Now, if you want something completely different that can use parts of your deck, I suggest Maelstrom Wanderer. It's always the deck I suggest to new players because it can be built in any way, it hits really hard, and it's pretty straightforward. You grab a bunch of green basic land ramp, hit 8 lands, cast Maelstrom and combo off into value. You can use all the U and R stuff into it, grab a selection of jank rares, and actually win games without spending $200.
